I use Navidrome [1] + an rclone'd S3 bucket on a Digital Ocean droplet. Works quite well for my purposes!

[1] https://github.com/navidrome/navidrome

The article is simply incorrect when it says that Youtube Music doesn't allow streaming of one's own personal library. It does - up to 100,000 songs.

This functionality has been available since 2020, around the time when Google Play Music (which always had the ability to play from a personal library) got absorbed into Youtube Music.

https://support.google.com/youtubemusic/answer/9716522?hl=en

Gonic running on my NAS via Docker + Ultrasonic over WireGuard (WG Tunnel for autoswitching when I'm not connected to my Wi-Fi).

Get NewPipe or yt-dlp and start building your own