I buy music, at least CD quality. I might splash out for 24-bits if given the choice (only because it seems to be standard on Bandcamp so for consistency I aim for the same in other stores), but not for > 48 kHz.
I upload to my server for archival purposes, but will convert to mp3 to sync to my devices. I buy CD quality poorly for archival purposes. I can’t tell the difference. Plus I have navidrome and I can stream, but having my entire library available at all times, even when offline, is very important to me.
I buy, in order of preference, from Bandcamp, 7digital, and only as a last resort from Qobuz. If even Qobuz doesn’t have something then I go on Amazon to buy the CD. I hate Qobuz ever since they removed the download all button. I remind them of it with the feedback form with every purchase. It was the reason I will prefer 7digital over Qobuz. I don’t know why you say 7digital is dead. They have up to date titles for the music I care about (metal). The only thing I dislike about 7digital is the http (no https) download, but I’d rather risk that than support Qobuz with its dark patterns.
Why not use KeepassXC? It’s a completely local encrypted db but it integrates with cloud storage apps like nextcloud for sync. It has plugins for integration with Firefox and KeepassAndroid is pretty smooth on the current Android OS.