You can more or less do this with apps that will stream your library off Google Drive. The one I tried demanded permissions to read everything in my Google Drive which seemed too dangerous, but if you had a separate cloud drive somewhere you could set it up pretty easily.
I believe it's too risky to have DMCA-able content in Google Drive.
Maybe, though I will point out that Google did/does offer this as a service:
https://support.google.com/youtubemusic/answer/9716522?hl=en