PC games are cheaper, you get free online on PC, mod support, tons of free games (mostly fangames, mods & indies), and chances are if you at least have a DX11-gen compatible GPU and a modern-ish CPU, you can play the latest games as long as you're willing to scale back on settings.
Sony & Microsoft (specifically Sony, since for them console is still a massive part of their total business model) need to find ways to actually address this. Stuff like Game Pass wasn't the answer, but raising prices on a gaming service required for online by 33% isn't the answer either (<ahem> PS+).
Until those issues are addressed, adoption rates slowing down will always remain a problem.
My guess would be that the vast majority of games are cross-generation. Most people are probably also waiting for a price drop on the consoles.
That's also part of the reason, tho many AAA and even a lot of AA games are now dropping 8th-gen platforms. Helldivers 2, Stellar Blade, Hellblade 2, Dead Space remake, Baldur's Gate 3, Tekken 8, MK1 etc. have no 8th-gen versions whatsoever.
It's really mainly GAAS (and of those, mostly F2P types like Fortnite) and sports games still regularly getting 8th-gen releases.