Why anyone trusts any streaming music service is absolutely beyond me. It will always get enshittified. I have 65GiB of mp3s I've accumulated from ripping CDs over the years and it used to be a burden to transfer around between machines. Now it easily fits on a thumb drive or microsd and it's easy to copy it onto all of my machines.
Yes, because you did not need to copy it to all devices. You could stream your own library at any device.
Probably you could set up a homelab server and there are tools/apps for streaming it to your own devices, but I havent bothered yet.
AND discovery part -- I'm feeling lucky let me listen to new music. If I liked it I bought it. But it's hard to find new music, get out of your bubble.