I don't think there's ever been a console generation before where the last generation was still getting big new releases this deep into the next one. The PS5 Pro is out now and the PS4 is still getting new games.
An analogy I might draw is the FIFA games, where FIFA 14 came out on the PS4 and PS3, but also the PS2 and Wii, which were just roster updates of previous years (no new gameplay features whatsoever), and clearly that was acceptable to enough people to give EA the trouble of developing, printing and distributing.
And people want to see that specific one NEW movie, too, not even just "the young". Even now, after all that has happened, Hollywood can still put butts in theater seats for a new movie, even though the attendees probably average several dozen movies at home and probably still have literally hundreds of movies they would enjoy as much or more than the one they are watching in the theater. A lengthy essay could be written on why, which I'll let someone else write.
But I can promise you from personal experience that a 2024 gamer has an easier time picking up and enjoying a 2014 game than a 2004 gamer would have picking up a 1994 game, to the point that it is not even close.
Checking a list of games from 2014... heck, I've got personal proof, my young teen recently started Shadows of Mordor. While it didn't "stick" (we got Skyrim somewhat after that and that has stuck, however, while initial release is 2011 on that the history is complicated and I won't complain if someone wants to forward-date that at least a bit), he wasn't like "oh my gosh this looks so bad and the QoL is so terrible I can't play this anymore". Others from 2014 include Super Smash Bros Wii U, Assassin's Creed IV: Black Flag, and The Last Of Us: Left Behind. Really not that dissimilar from what is being put out today.
Whereas 2004 to 1994 is the delta between Grand Theft Auto - San Andreas and Sonic 3 and Knuckles. That's huge. Yes, I'm old enough to have been there and I can you from personal experience that in 2004 "Sonic 3 and Knuckles" was very definitely legacy in a way that The Last Of Us: Left Behind is not. If you tell someone today that you just started the latter, they might wonder why you're late to the party but they're not going to think anything more of it.
I'm sure D4 is more modern, but the difference from D3 is nowhere near D2->D3 for the same time span (12 years).
It's hard to release new live-service games too. Many people will just be happy to play LoL for the rest of their lives.
But that compatibility is not achieved with emulation, right?
The PS6 can hopefully keep compatibility with PS5 and PS4 in a similar way. Unless we are nearing some sort of ARM horizon for consoles, that is.
The documents accidentally leaked from the FTC vs. Microsoft trial revealed that Microsoft was at least considering switching to an ARM CPU with the next Xbox generation, but they hadn't decided yet at the time those documents were written. Either way they would still use an AMD GPU, so it would be AMD+AMD or ARM+AMD.
A platform inside the platform.
That is why console sales are so bad, in comparison with previous generations growth sales.