I know the question is rather awkward at first and I am possibly overlooking something, but I would like to know something I really don't understand.

In the past I have used modified versions of Spotify and they are fine but obviously no modified version allows you to download songs because it is a premium function at server level and honestly I would like to have my songs on my device, so if I don't have internet I can still listen to them.

After those modified versions of Spotify, I have used apps like ViMusic, Spotube and SimpMusic which are basically Youtube Music apps but without ads and with more features, including downloading music, the problem is that they do that at the level of the app itself, not in a separate file. And I love these apps and I can not recommend them enough but my phone is a little old and I see 0 need to change it since I use it for basics usage and although this can sound dumb the interface of these apps are full of blur and unnecessary effects that make my device slow, including Spotify, and I don't like Spotify Lite because I feel it is a very trimmed version of Spotify.

So this is where my question comes in, for those who exclusively download music, how do you discover new songs? Spotify's recommendation system is great and Youtube's radio mode is very good but obviously I need to use Spotify or Youtube Music to use it and I prefer to use light apps for local playback because of what I already mentioned.

Edit: Thanks for all the recommendations! I never thought this post would get so many answers and there are too many comments to answer one by one, but I admit that the old-school method of reading blogs or magazines works well, and I also like the idea of sites like Last.fm or discogs.