Take a look at Musicroameryou type in a favorite artist and it uses the spotify recommendation stuff to find similar artistsif you find one that sounds nice then you can then create a branch of artist that are similar to them(probably a horrible explanation, just mess about with it for a minute and you'll get an idea how it works)

I've personally used it to find quite a few new favorites since ditching Spotify in favor of a self hosted Navidrome server

as for FLAC downloads check out Qobuz, which has unlimited DL plansalternatively if you would rather sail the seas, search up Firehawk52 for a guide