it's funny, I used to think and care about this (or thought I did) back when 1080 was the common thing and 4k was new and exotic, but now I really don't care.
I think what changed was the realisation that even with 4k hardware in theory, what you're actually seeing is so variable based on bandwidth and different services' support for different shows you basically don't know anyway and thus it doesn't really make much sense to care about it.
Besides which, you realise that things that are made to be more enjoyable on 4k, like where that would actually make a difference to how good it is, are probably not that much worth watching anyway outside of demos. Certainly it's not, for example, a factor on which you want to be choosing what series to watch.
Exactly, streaming video is so compressed that 4k will just let you see all the compression artifacts more clearly.