You are right, PS5 doesn't have great apps. However, I don't think it's Sony's fault as each vendor does their own app and decides what to support. I guess so few people access these apps through a PS5 that is not worth the investment. Also it could be related that PS5 didn't support Atmos on launch and they haven't gotten around to add the support.
For example, if I remember correctly only Apple devices support Atmos with Apple Music. There is nothing Sony (or other brands) can do about it as Apple has decided to keep that option exclusive.
That said, listen to what everyone else is saying: The WebOS apps are pretty competent and are up to date in format support. As an added benefit you would be consuming less power when streaming.
I used to have a C1 and now have a C4 and the apps are pretty competent. I have an Android TV but there is no need to use it (not the case with a Samsung KS9000 where the apps offer all kinds of support but the performance is poor).