I mostly use mpv to play local music nowadays. (Most of the music I play is streamed using a Navidrome server with Feishin as the frontend.) Back when I did use a proper audio player on Linux, Harmonoid was my go-to.
I've been very happy with Navidrome. I have it accessible on a subdomain, so I can just use it from wherever I want. Feishin is a great frontend for Linux desktop, and Tempo is a great frontend for Android.
My friend uses Jellyfin instead of Navidrome, and he's also happy with it. Both the frontends that I mentioned work with Jellyfin as well.
For media, I host the some of the arr apps, qbittorrent, Jellyfin, gpodder2go, and navidrome. For personal photos, I host PhotoPrism. I host a file sharing service fileshelter, and a link shortening service chhoto-url. I host Wiki.js for mostly recipes, and some notes. I've recently started hosting Forgejo for my git repos. I also host SageMath for computation, it's especially useful when I only have my phone with me and need to use it. I use caddy as a reverse proxy and serve these through a VPS using a Wireguard tunnel.
At that point, you're just paying for training Microsoft's AI.