They screwed up. Game performance was worse than it should be this service should have rivalled next-gen in performance with zero upfront costs. Instead the performance in some areas failed to match Xbox One X.
Any hype was also killed by them destroying their one advantage (no hardware costs) by having the stupid founders edition (£129) be the only way to use the service for the first 6-8 months.
It's not impossible for the service to make a comeback, but they really messed up the launch big time. Should have waited a year.
This seems about right to me. They rushed it. I've noticed that MS has stopped talking about XCloud being right around the corner. They saw what happened with Stadia, and realized that streaming ain't gonna work until its better than that. So, we could say that's a possible silver lining.
As for game ownership..... I don't see Stadia as any different than any other digital game purchase. Lots of games require you to be online to play. So, as soon as they stop supporting that, the game becomes unplayable. No different than Stadia, really. Personally, I prefer physical media so that I can resell my games. But, as I get older, the convenience of digital is becoming more appealing. Stadia strikes me as even more convenient (no waiting for download), and about the same in terms of really owning the game.