This post made me wonder whether they quietly removed the feature. It's still there though. All my uploaded music from the Google music days is still there and there is still an option to upload new stuff.

It's not as well-integrated as it use to be in the Google Music days though.

It's incredibly painful to do this with a large library, as they've stopped supporting the desktop uploader. It's all drag-and-drop uploads, so it's not easy to keep it in sync with a folder of music.

Also the playback experience is painful and uploaded files are poorly supported across devices like Google Home, where it constantly wants to do playlists or mix in other music. I'm not sure Google Home even supported playback of uploads, though I abandoned the service shortly after the Play apps went away.

Exactly right. I'm very confused by all this because I literally stream music from friends and local bands that I've uploaded to my personal YouTube Music account.