Used to think it was the PS5's SSD that was the game-changer. Allowing for in-engine cut sequences seamlessly meshing into gameplay. But now I think it may be the 10 Teraflops Navi GPU that devs will seek to unleash ;)
Remember that games take years to develop and it takes time to build engines that utilize new hardware.
RDNA 2 ofc is also a very good architecture with great features
I think the real thing to be looking out for is how developers utilize the crazy overhead they have. The Touryst leverages newer consoles to perform 6k/8k supersampled antialiasing without dropping a frame. Minecraft with shaders is finally just... viable. Hell, I wouldn't be surprised of Sony introduced some emulation layer to play PC games (a-la Proton) if their competition with Microsoft really starts heating up. Really, the hardware is the least interesting part of this console generation. Building a robust software experience on them, however, is where things get interesting (at least to me).
If anything, I think these kinds of comparisons underscore that even in a world where consoles are using mostly PC-originated components and architectures, there are still massive wins to be had when a developer can put their effort into targeting a single hardware platform (or a small number of them, eg pro and non-pro) rather than chasing a million interop issues across the infinity of permutations of in-the-wild PC hardware.
We finally have high performance SSD's which revolutionizes streaming. we have advanced shaders that should allow extreme levels of geometric detail, custom audio engines and more.
Last gen felt like a compromise with machines using outdated hardware, this gen is state of the art with tons of potential