Depends who you ask. Many would say supporting companies that are so anti consumer is in a meaningful way contributing to the problem.
Many would argue using "free" media sources is more moral since you're not supporting what many consider to be evil companies.
The thing with paying for YouTube is that you’re giving Google money for them to get more data on you. Logically that seems like a bad deal. I get that you probably don’t mind it, but other people rightfully do.
> Can download video on most (all?) devices
Is that download as in “they are available offline in the app” or as in “you get an MP4 that you can watch in your preferred player”?
It's very immoral from that perspective.