That's because your vision is being clouded by main character energy.
The people most chiefly involved in many of these games are no longer their respective studios and/or those relationships aren't the same anymore and/or there hasn't been the financial incentive to make these games.
We're talking about a video games market that continuously saw growth of new players for multiple generations. Trust me, financial incentives existed for a long while for some of those SIE AA-tier IP to come back. SIE just either didn't capitalize on them, didn't do so the right way, or ran into funding issues to justify the investment (particularly during middle of the PS3 gen, which had a knock-on effect even into the early PS4 years despite PS3's recovery during 2010 - 2013).
As for certain people not being involved at the studios any longer, well for IP that SIE own, they could have certainly found a 3P studio who'd of been interested in continuing the IP. Again, they just either didn't find the right studios, or never tried.
Let's examine this further starting with PS3. Focusing on the best selling franchises that did not appear on PS4.
The first franchise that hasn't gotten a direct sequel but sold well would be LBP, but let's think about LBP3... Media Molecule didn't develop the game, they farmed it out to Sumo Digital. The first game sold 4.5 million units and the sequels sold less. Even then Sony greenlit Sackboy Adventures...
Let's not pretend market conditions at the time didn't have a negative impact on LBP2's sales. Not only was PS3 in a rough spot still, but market tastes had shifted heavily. Tastes had began to change and only platformers with very well-known characters like Mario, Sonic or Rayman had large viability. Also have to consider the commercial market of new game releases at the time of LBP2's release, plus Sony's marketing efforts (or lack thereof).
All of these things impact a game's sales potential in a given environment, it's not as simple as saying "gamers didn't care" or "the game was bad".
Next? Motor Storm, which also got declining sequels and the studio was shutdown after DriveClub.
You mean the Driveclub that was mismanaged and only half-finished when SIE released it in 2014? Yeah, considering that, no wonder the studio got shut down.
Shame, too. Very talented studio, and Driveclub is
still one of the Top 5 best-looking racing games ever in spite of running on a "potato" base PS4. I'd even argue most new racers look worst comparatively outside of image quality and some modern anti-aliasing or filter effects.
Next Heavy Rain. We saw Sony continue to greenlight Quantic Dreams games but after their contract with them ran out they didn't renew because of the issues surrounding David Cage. Heavy Rain got remastered for PS4.
Next is Resistance, which sold 3 million copies. Insomniac's Spider-Man sold 20 million copies. They MUST hate Resistance right? Spider-Man 2018 and Miles Morales have sold more than all of the previous Insomniac games combined.
Resistance came out at a time when Halo was at its peak, and as good as that game was, it was not on Halo's level. Or Gears of War's for that matter, also a 360 exclusive back in the day. But the sequels did improve on the formula, for sure. In any case, Resistance isn't the type of game I'm referring to since it's a gritty sci-fi shooter, and the market isn't really struggling for that type of game in terms of presence.
It's a well-fed niche in the market, and on PlayStation. Even in terms of theme and template if not so much gameplay genre, SIE's 1P AAA hits a lot of similar beats.
This list gets worse and worse the further back you go...
What PS2 franchises that sold well were abandoned? Jak and Daxter? Tailed off and was replaced by Uncharted and TLOU. Uncharted hasn't gotten a PS5 entry except the port. Does Sony hate it too?
SIE probably don't hate Uncharted, no. But Neil Druckmann might
