I've read the other posts ITT since this morning and I'm seeing a lot of people throwing technical specifications around, but no one has actually answered the more important question: what is the industry and business case for a PS4 Portable right now?
Let's start with industry first. Sony already have the PS5 out there, and they'll be launching the PS5 Pro later this year. They also have the PSVR2. So by the end of the year, they will have at least two systems of different performance specifications on the market for developers to focus on; while the PSVR2 is technically also there, it isn't it's own "system", and market-wise is not really present at retail when it comes to demand (seemingly).
So you already have the PS5 which is the baseline, and then we have the PS5 Pro which will be the upper-end. Now some of you are saying they'll put out a PS4 Portable, which would fall below PS5 and be the floor in terms of specifications to target. That's three different performance profiles developers would now have to account for, if this is a PS4 Portable meant to get current-gen games. Yes, I'm sure the PS4 Portable would have some form of PSSR in it to help with scaling, but it's also much easier to scale up than it is to scale down. I said this years ago WRT Xbox Series S vs X. That doesn't suddenly change now just because we're talking about PlayStation.
A PS4 Portable also would present some issues with actual native PS4 support for new games, if the downscaled versions of those games are leveraging feature set functions only shared among the Portable, PS5, and PS5 Pro. The PS4 as we know it, doesn't have those features at the hardware level. So developing downscaled versions of games originally made for PS5, to run on a PS4 Portable but ALSO meant to run on actual PS4 consoles, could require even more optimization workloads for developers, slowing down development times.
The PS4 issue in that regard becomes a moot point if the goal on Sony's end isn't to support the base PS4 in that way; they would likely be more interested getting PS4 owners to upgrade to a PS5. And I guess this can segued into the business-side argument. In that context, perhaps having a PS4 Portable can be a better entry point for remaining PS4 owners to jump over into the PS5 hardware ecosystem, especially in markets where home consoles aren't that strong, such as Japan. I've acknowledged this multiple times.
However, those particular gamers are probably going to be more price-conscious, so let's just think about this. If the PS Portal, a streaming-only device with "weak" (compared to a PS4) mobile components goes for $199, how much do you think a PS4 Portable is going to be? At least more than $199, for certain. How much more is a crapshoot; maybe the Portal gets a price cut to $149 or even cheaper so a PS4 Portable can hit $249 or $299. Because realistically those are likely the only price points where it can work as a bridge to get remaining PS4 owners (who'd comprise a big bulk of the target audience) to the PS5 ecosystem.
A $249 or $299 PS4 Portable, probably releasing sometime in 2025, that can play all PS4 games and play scaled-down versions of PS5 games, in a portable gaming market that'd also include a (likely) $399 Switch 2 and either next year or 2026, both a new Steam Deck and probably some Xbox handheld. All three of those are going to have performance at least on par with a PS4 Portable, potentially better in some cases. Whether they can do that at $299 or less...personally I don't think so, but for various reasons. Nintendo: they'd take a loss and they hate that. Valve? Not enough volume for economies of scale. Microsoft? Likely similar situation to Valve.
So if this PS4 Portable is real, to work as a business case Sony have to REALLY target those PS4 customers (and customers like them say in the Switch ecosystem, or Xbox ecosystem) who are ready to jump to current gen within a year or so, but want an affordable portable/handheld option, that can also play a big backlog of games & play current-gen releases natively. I don't care if SIE hate the idea; they would have to aim for $299 and nothing more for it to be worth a business venture in the market, the way the market is looking to be like by next year or slightly later.
Why don't I mention current PS5 owners as key targets? Three reasons, actually. 1: the core in that group interested in new hardware would be more interested in MORE performance, not less, so they're more interested in a PS5 Pro. 2: those who are core in that demographic would, if wanting to play PS5 games on the go, likely prefer the Portal's at-PS5-fidelity option (albeit streamed) vs. lower-than-PS5-fidelity native portability (and in fact a good number probably already have a PS Portal). And while a smaller reason (plus some will disagree with me), 3: some in that core market are aware enough of SIE's PC strategy to probably consider a PC-based handheld for portability needs vs. a PS4 Portable, especially if they mostly play 3P games & ESPECIALLY if SIE (erroneously) push for Day 1 PC support of more or all of their games (particularly without their own launcher).
That is the business-side of the question mostly answered, but it depends on a lot of factors. How does Sony avoid not having devs strain their resources optimizing settings for games to run on a PS4 Portable? How do they do that while ALSO asking them to optimize for the PS5 and PS5 Pro? How do they ensure game scope doesn't take a hit if the PS4 Pro is supported? Will supporting it be mandatory for all publishers? How do they handle the production logistics of the device balanced with production of the PS5 and the Pro? How do they ensure they have something flexible enough to remain a cheaper entry-point device into the current-gen market when compared to competing portables already own and planned to release within the next couple of years?
This is why in my opinion, and especially with the PS5 Pro seemingly coming, and a PSVR2 needing resuscitation, that Sony's better option for now would just be to improve PS Portal production. Get cloud gaming going for the Portal (it being listed as its own device in NPDs months back suggested this could have been the plan, since that was done at Sony's request), maybe a redesign that can present a variant in a more "traditional" portable package, and get more games support for PS1/2/3/Vita/PSP both streaming and native between PS5 and the Portal (the latter probably not able to do native BC for certain systems without some revised specs).
If PSSR turns out very well, and Sony can develop other complementing technology for it to address other areas of the graphics & logic pipeline that handle scaling (both up and down) as much as possible so devs don't have to micromanage as much, that'd be great. The PS6 generation would be an optimal point for a "capable enough" home console paired with a downscaled handheld that can natively play lower-setting versions of PS6 games, likely native PS5 games, PS4 games, prior PS consoles & handhelds as well.
What I'm concerned with, if Sony do put out a PS4 Portable this gen (such as if next year), then it's just so much hardware in so little a time frame. It'd mean, in the span of only two years, they'd have released: PSVR2, PS Portal, PS5 Pro, and a PS4 Portable. Do you know what other platform holder pushed out a ton of hardware in a small space of time? SEGA. Yes in SEGA's case there were additional problems, such as their myriad of systems all having very different architectures and performance abilities, plus in certain cases incompatible software libraries, making things increasingly frustrating with them during the 4th-gen > 5th-gen transition.
Even so, no platform holder is immune from making a similar mistake, and I think a PS4 Portable coming so soon from Sony would be pushing a repeat of that type of scenario. Amid the things they're doing well, and some of the things I feel they could be doing better, I don't think it's wise of SIE to run that risk. Just do a Portal revision, get stock for that thing better, and make it easy for devs to support the PS5 Pro once that comes out. Portal, PS5, and PS5 Pro are the only systems they really need at this time; save the PS4 Portable for a better-realized PS6 Portable (and an aside: don't give up on VR/MR, although that is just wishful thinking personally!).