I used foobar2000 for years and years - it’s everything you could possibly need, gets out of your way, and you can funk up the UI if you really need it.
But I have to be honest and say I’m now just using streaming services and vinyls. Having a massive MP3 / FLAC / OGG collection is no longer something I aspire to, especially given how hard it is to get legitimate, DRM-free files from the artists I enjoy (and who knows what will happen to Bandcamp after the sale).
Physical ownership has become far more valuable to me. All my favourite artists sell vinyls at their shows and there’s something beautiful about seeing album artwork in 12x12” instead of 128x128px.