Chiming in as a happy Plex lifetime pass user, using it for my FLAC music library as well as other media.
I do however, still maintain a Spotify account for primarily non-English music, especially new releases, which seem incredibly difficult to find anywhere else.
I find that iTunes has the largest access to non-English music, making it very easy to find and buy (compared to having to import the album or single and ripping it), even easier than pirating for a lot of these albums which get zero support outside of hyper niche and exclusive trackers.
The only real downside is navigating iTunes is a huge pain these days. Trying to explore the sub-genres they used to have kicks you back to the main store page. So you have to know which artist/album you're looking for.
I do however, still maintain a Spotify account for primarily non-English music, especially new releases, which seem incredibly difficult to find anywhere else.