If you were a writer, then books might be different to you. Or if you were a record collector, records might be a different.
Yes, it becomes problematic when people apply that attitude everywhere but sadly it is likely where we are heading with all the consequences it will carry. Most people are addicted to convenience and will sell everything to attain it
You're repeating this benefit -- and it is an undeniable benefit -- but the other issue you're not giving any weight is that other people have other priorities that can be more important than ownership -- such as a finite amount of money to spend.
Of course, ownership is wonderful -- IF it doesn't cost more, and IF it doesn't cause more inconvenience, an IF it's even available. In other words, the concept of ownership can't be considered only in isolation.
I know all about ownership as I have over 2000 CDs that I legally purchased and ripped losslessly to FLAC files using custom scripts. Would I recommend "music ownership" like that to most others who have a casual relationship with music? No. The Spotify subscription with access to 100 million songs is much cheaper and a better financial deal for most regular listeners than buying individual CDs or individual songs at 99 cents at a time from the iTunes store.
Does my 4TB harddrive of full of *.flac files that I own let me "do whatever I want with it?!?" Well... it's not a simple "yes". E.g. My friend's music streaming subscription lets her instantly load up any of the 100 million songs to listen at the gym. On the other hand, my iPhone doesn't have access to my entire music library because it only has 256 GB of space. I guess I could somewhat duplicate the "streaming" aspect if I go through the trouble to set up some Plex media server with a vpn TailScale or Cloudflare Tunnel back to my home server. But now I get into the realm of "my music CDs owning me" instead of the other way around. I have paid over $20k in music CDs ownership to have less convenience and usability. So others paying $11.99/month for more music than my personal library with more convenience to play on any device doesn't seem so ridiculous.
But can't Spotify raise the subscription from $11.99 to $13.99 on a whim? And can't they remove Taylor Swift from their catalog without warning because of a licensing dispute?!? All true. But those negatives are outweighed by the positives of cheaper price, more music, more convenience.
Ownership is not the be-all-end-all. It's only one aspect of experiencing music.
I have conflicted feelings about all the money I spent on owning CDs and vinyl records. But then again, I didn't consider other options as I did all that ripping 20 years ago before the existence of Spotify and mobile phones.
Btw, I actually set up a server using Raspberry Pi with 1TB of storage for my music collection to be able to access it from anywhere. Funny that you mentioned exactly this case.
As for the recommendations, occasionally I listen to the bandcamp feed. Not even sure if it's based on my followings. And before that I was using one specific forum to learn about new stuff. It's not there anymore. And I don't like the idea of algorithms telling me what to listen to.
As for the rest. The issue I see with the subscription approach is exactly what you described. People start getting used to it in other domains other than media consumption. Like cars for example, car brands introducing subs to enable your seat warmers or whatever that technically is already there, but for you to use it you have to subscribe. It's a matter of time this starts spread everywhere. And when it does there will be people who will come up with a number or reasons why it is actually fine and everybody should just go with it.