I signed up for Stadia and was really impressed with it. I played dozens of hours of Destiny 2 and really enjoyed my time.
Then I installed Destiny 2 on my home computer and streamed it to my work computer. (I got permission, it was during lunch, etc.) The lag was noticeably less.
Likewise, I had the LOTR Lego game installed on my home PC, and streamed it to a laptop in the same house. The lag on the timing-related events was absolutely noticeable.
Sure, you can play from the cloud and have a lot of fun, but it's definitely not as good as playing locally, and can't be because of the lag.
I imagine that many people think internet latency is better than really it is due to the sophisticated predictive technologies currently used in games.
Of course, it especially shows as network performance degrades. (I tried streaming a game the other week on cell tower tether from a hotel with bad wifi and the input prediction was a bit like trying to semi-blindly navigate a PowerPoint or HyperCard deck of the game. Felt like classic Myst nodes with a worse game play user experience.)
No and it's not really close, especially for first person shooters. That few milliseconds delay makes a HUGE difference in the feel of the game and ultimately how well you perform.