That's a consumer-level understanding of UE, but it's off-base to think that UE5 is just a delivery system for Nanite and Lumen (or, for that matter, that games will be better-looking by default because of Nanite and Lumen.) There's lots of reasons to work in UE5 (especially now that it has proven stable for product launches, and that studios are pulling from a talent pool which is gearing up on the new systems,) and ultimately, most Unreal Engine games will be made in UE5 over UE4 just for the production advantages, regardless of how advanced the project is in its tech use.