After PS4 Pro there was still 4 years till PS5. With COVID, the PS5 Pro being a year later in comparison to the PS4 Pro and Microsoft stating in their court documents that they expect the next generation of consoles in 2028, analysts think we'll only get the PS6 in 2028 but it could change if PS5 sales don't pick up.
I also think people misremember how much stuff there was when the PS4 launched.
Some hits of the first 4 years of PS4 :
Infamous Second Son, The Order 1886, Uncharted 4, The Last Guardian, Horizon Zero Dawn and Gran Turismo Sport.
The first 4 years of PS5 :
Spider Man Miles Morales, Returnal, R&C Rift Apart, Horizon Forbidden West, Gran Turismo 7, GOW Ragnarok, Spider-Man 2, Helldivers 2, Stellar Blade and Astro Bot. Only difference is 7/10 were PS5 exclusive instead of all of them.
Most of the action of the PS4 era was in the last 3 years - God of War (2018), Spider-Man(2018), Days Gone (2019), Death Stranding (2019), Ghost of Tsushima (2020) and The Last of Us 2 (2020).
In the pipeline for the next 4 years we have GTA 6, Death Stranding 2, Marvel Wolverine, Ghost of Tsushima 2, Naughty Dog New IP, Santa Monica New IP, Bend Studios New IP, Bluepoint Original Project, Horizon 3, Housemarque New IP and Bungie's Marathon (ok this one is probably going to flop lol) which is quite a lineup till the PS6. The best is yet to come.