Agree with all of that, but technically it wouldn’t be a PlayStation Portal, it’d be a PS4 Portable.
I really like the idea of of Sony making a handheld each gen that doesn’t have its own distinct games library, but instead plays the previous gen’s games.
Considering PS4 is still getting new games 4 years after PS5 launched this wouldn’t be unfeasible.
Handhelds are never going to work 100% with most games designed for 4k screens.
OTOH, if Sony could do what they did with the PSP but reengineer it to get the same specs as a PS2 console - they could easily bring PS2 games to handheld and a TV-console.
Put the same updated combo EE+GS chips on new PS TV-consoles and reopen the PS2 to developers as a digital-only platform that takes advantage of the DualSense feedback and 3d audio.
This new modernized PS2 TV-console platform would be 100% handheld compatible and digital-only games would be bought once and show up on both devices.
They could add in hardware PS1 functionality for both and have a massive amount of PS1/PS2 content that just needs to be modernized to work with the newer controllers and audio.
The handheld could have a detachable portal-style configuration or it could be simpler and just look like a really nice OLED smartphone that's the right size (likely more 'square' shaped and thicker((for batteries, speakers, build quality)) than most smartphones) for an ideal game monitor. The smartphone could be used with ordinary DualSense controllers wired so that lag's minimized and the screen could be mounted to a dock that connects it to the DualSense controller. Basically a handheld console built around the same controller that the TV-console uses. Alternatively it could have a Portal-style DualSense handle system that connects to the handheld in the center. The handheld could have 2 user replaceable Sony rechargeable batteries arranged so that both batteries could be swapped on the fly one at a time without loosing power.
All of the power would come through the central handheld so to plugging it in via a wall USB charger would keep everything going just like swapping out the batteries.
Handheld would have stereo speakers, a 3.5 audio jack and work natively with the Pulse 3d headphones.
Some kind of slick dock that's got enough weight to be solid would connect the handheld to TVs via HDMI out and the OG "AV Multi Out" for people with component/composite.
Dock would have simple unidirectional slots for charging battery packs.
Dock would have 2 MagicGate memory card slots situated above controller ports for 2 hardwired DualSense controllers.
Memory cards would be extras that generate a unique bootup experience based on the game save data.
Dock could have a big HDD and serve as a repository for users games and other content.
Effectively an updated PS2 handheld that's been reimagined to incorporate all of PlayStation's best features from across generations.
Users could buy into the platform with just the handheld and a controller expanding it to a low-lag TV-console and keeping it alive via replaceable batteries.
Unlike the situation with the Switch, a digital-only PS system could be kept alive indefinitely as a perpetual generation.