It supports up to 100k uploads and you can stream and/or download your uploads on web/iOS/iPadOS etc. https://support.google.com/youtubemusic/answer/9716522?hl=en
It's not as independent but if you're already paying for YouTube Premium it seems reasonable if you don't want to host your own media server.
TIL they somewhat resurrected Google Music and raised the limit (I think it was 20k on that). I used Google Music for years because it seemed like only Spotify and them figured out reliable caching on mobile, other services when I'd lose signal they'd give up trying to stream... even noticing recently apple music is not super reliable with that.
The UX isn’t perfect (still see a ‘download’ option for things already downloaded, for example) but it’s not terrible.
I still miss my iPod from time to time, though.
You can play uploaded songs in the background, ad-free and offline—even if you are not currently a YouTube Music Premium subscriber.
Did not expect that.