I'm a YTM subscriber too, have been since Google Play All Access beta. While it works for my needs, I fear that AI is coming, if not already, since anyone can upload anything and classify it as Music. I usually stay with well-known artists, but like to listen to ambient stuff, which is a prime target for AI generation.
The algorithm still suggests some forgotten classics. On YT music I can find entire albums of somewhat more obscure yet excellent artists that are completely missing from Spotify.
I pay for Youtube with a family sub. Good value for me.