I wonder if e.g. Fifa gets another offshoot on the PS4 with Fifa 22. Since it was still like that back then, the games were still developed for the old generation for a few years, e.g. Xbox 360 still got the full FIFA 15 and not just a graphic DLC or this time the developers save the effort for 4 (5) consoles to optimize the games. In brackets 5 because of the switch because not all games come on the switch.
For a while, the PS4 will certainly still be supported. What use is it to you as a developer to only develop for the PS5 when 1 million users worldwide have a PS5 and 200 million users have a PS4? You will definitely not want to leave the latter market lying around. Support for the PS4 won't wane until the average Otto gamer has a PS5.
On the contrary, it is to be feared that further development for the PS4 will initially be carried out and that the PS5 versions of these games will not exhaust the PS5 at all, but only contain a few small graphic optimizations. So basically you run code developed for the PS4 (and its capabilities) on the PS5. Native PS5 games that would not run on the PS4 will initially only be available as promotional games from Sony in order to push the new console onto the market and give it a right to exist.
Therefore, even years after a new console has been released, the games available for it keep getting better, although the hardware remains the same. Because of this and because the programmer's practice and experience with the new hardware increases, so that more and more can be squeezed out.
Games for the PS4 will definitely continue to come! With many (now upcoming) games, if you buy them now for the PS4, the upgrade to the PS5 is free!
Definitely. On the ps5 you can only play ps4 games with a ps4 controller because the ps5 has different features. Generational crossplay should also be possible for some games (e.g. Play FIFA on ps4 and ps5 together! I don't know exactly which titles these will be), and of course there will also be a free ps5 version for owners of some digital ps4 for most games Give game versions! So it is still a long way from the race.