I have no clue why so many people here are so much against options.
If the people have not enough money to afford the proper hw, be it a console or a beefy enough PC, but have already at least some supported display and also an internet connection, which disqualifies probably still quite many, this can offer fun stuff for free. If the servers are not too far away and the experience is decent.
I use spotify for free since years. So far the ads are not really annoying, and mostly I can listen to what I want beside inserted suggestions I don't ask for. I think there is one rather short ad block every half hour or something, unlike youtube which craps on the content sometimes every 5-10 minutes.
The costs for game streaming are higher than for music and video though, so MS probably would need to add a ton of ads to make that somewhat viable beyond just fixing young poorer, but probably already not actually poor, kids in hope that they become big spenders later on.
But generally I would not be opposed to something like that myself. I barely have time for evrything I want to try but trying eg Starfield for free. ust now and then some single title. I would do it. Some games are not much worse via streaming and require no super fast lag free connection. So instead of buying a sub I would barely use, or hw I don't really want, just jumping into MS's world in between, would be fine.