Update to a newer SoC; NVIDIA's latest chips at this thermal displacement are like 4x as fast + would easily run PS4 games
Upgrade the controllers to be more reliable + feel better
That's pretty much it; the OLED model is fine as far as physical design + screen, it just needs more competitive performance and to fix the Joy-Con drift nightmare
They did. It's called the Vita and it's still amazing even after Sony dumped it. I have one a friend cracked for me, and any game I could possibly want to play runs at a crisp 50 fps with no fluctuation. If only they had marketed it better.
I have one as well, but let's not overpraise it. That handheld isn't a "ps4 as a handheld" (obviously since the vita came out 2012 or 2011 cant remember which). And sadly it struggles to play its generation's games (i.e. Borderlands 2 (one of my favs on vita) runs at 20-40 fps).
There are great games that showcase its abilities auch as the killzone game, but that was made for that system.
And let us not forget that it wasn't a successful handheld. There is a reason sony hasn't made a new handheld device since.
I agree, hall effect joycons SoC to something that's less than two years old and maybe a little thicker for enough battery to match runtime and a tiny quiet fan.