As a GFN user for the past 14 months I disagree. It's more than acceptable performance even when playing competitive multiplayer games like League of Legends and Planetside 2.
I do agree however that Stadia sucked as a product. Nobody was going to buy into their ecosystem if they can't opt to download the games onto their own PCs like Steam. Too much lock-in without that aspect, and without any guarantees that they were going to refund customers if Stadia ever sunk it just made it DOA
But that's not the perception GeforceNow has. If I ask around what people think it would be then most of the gamers I know wouldn't even consider it unless they had no other option.
Games are already fiddly when it comes to latency. Adding another fiddling layer inbetween just sounds more painful.
I do agree however that Stadia sucked as a product. Nobody was going to buy into their ecosystem if they can't opt to download the games onto their own PCs like Steam. Too much lock-in without that aspect, and without any guarantees that they were going to refund customers if Stadia ever sunk it just made it DOA