Xbox Game Pass not worth it

I wondered about Game Pass and game subscription services in general, but since there are often multiple months when I don't play any games, I didn't want to commit to a recurring expense. Then I received a free, three-month trial voucher from a friend. (Thanks, Sashenka! <3)

Some facts relevant to me and my usage: first of all, I prefer owning the things I buy. When I can, I buy games on GOG and actually make backups of the offline installers for every purchase. I do still use their Galaxy client - I enjoy achievements, save sync, and the like. But the fact that its usage is optional really is important to me.
On the other hand, most games I realistically only play once and then don't return to them, so a subscription might not be a bad deal. It also makes just randomly trying out games a lot easier, when there are no additional costs.

But I knew I wouldn't continue the subscription even before the first month ended. Most annoyingly, there were nonsense technical problems. Games didn't start. I was only greeted with black screens. I was prompted to log in nearly every time I launched a game. I was able to resolve some of those issues eventually, but I still missed some games because of them. For example, I wanted to play a short narrative game Venba that was supposed to be two hours long. Instead I spent an evening or two troubleshooting to figure out why it wouldn't start. After that, it got taken off the Game Pass, so I got to the middle of the game, and the next day I simply couldn't continue playing.

Then I started playing SteamWorld Dig 2, a single-player platformer game. When I wanted to continue the next day after work I couldn't because Game Pass had a service outage of some kind.

Later I tried Cassette Beasts which worked, but it seemed like the kind of game that I'd enjoy playing on and off every now and again. That means after it gets kicked out of Game Pass, I'd still have to buy it anyway. And I'm definitely not buying anything on a service that prompts me for a microsoft login (or tells me my store login doesn't work) every darn time I try to start a game.

Then I didn't play any games during the entire August.

I'm really glad I got to try the service for free. The game selection was good enough. But given how many technical issues there were, the fact that I'd also have to pay for months where I played nothing, and the fact that by the time I get around to playing again the game might no longer be available - it makes no sense for me.