I'm surprised at how many people are discounting what Stadia offered. My reasons for not investing in it are pretty much just data caps and lack of trust in Google.
Also, I've owned every Playstation since PS2, and I've never played an online multiplayer game on one (with the exception of Journey, which does so silently), nor do I give the slightest damn about achievements.
If I could just play the game and not worry about the hardware, I’d be tempted as long as the service was reliable. Had Stadia become a real business, I’d have jumped on in 5 years or something.
They probably spent millions on getting the whole Ubisoft and EA catalogues on Stadia. There was also Red Dead Redemption 2 quite early on, Football Manager 2020, Destiny 2, some Doom, Hitman, Cyberpunk. Not to mention hundreds of indie games. Saying Google didn't invest enough is showing lack of knowledge about the platform.
Thet didn't need an exclusive, that money would have been better spent on convincing more studios to port, marketing. And reassuring potential users with a promise for a refund.