OK. I know I'm about to get blown the fuck up but... You will own nothing and be happy. But. Like. Unironically.
I really don't think most people want to manage thousands of music files on their computer. Or hundreds of movie files. Or thousands of picture files. Or hundreds of video game files.
There are definitely options for doing this, but people who go this route are usually tech elite nerds. Not your parents or grandparents. Not normies.
(I self-host Navidrome, Jellyfin, Immich, etc.)