That's not the case actually, UE5 is in more games than TV stuff, it's barely being used in some Disney stuff while it's used in countless AAA and indie games. Game devs weren't given a false impression it's just a lot to take in at once and learning the tools takes time.

Lighting, materials and post processing. Something that seems so easy to change yet everyone uses defaults and Megascans...

The technology exists (in UE5 at least), you can use Control Rig to trace down on the character mesh... It's just a detail that no game dev actually cares about which is sad