if you can afford to pay monthly for 400mb/s internet + paying for geforceNow surely you can afford better computer. This service makes no sense to me.
That's simply because you fail to see the bigger picture. It's the declared strategy of all big IT corporations to move --all-- computing to "the cloud", games are just one piece of the puzzle here (albeit a very demanding one).
Xbox is turning into a streaming platform for games, Microsoft already stated that they no longer care what hardware you want to use to play Xbox titled. You probably can even expect an Xbox streaming client for Sony's Playstation rather soon.
In December 2019, Microsoft launched a product called "Windows Virtual Desktop". It's exactly what it says on the (virtual) "box": A virtual Windows desktop, running in Azure. With the desktop versions of Office. And whatever other software you want to install on it. All you need is an HTML5 capable browser to use a Windows machine this way. And again, Microsoft doesn't care what hardware or operating system you use to access this virtual desktop.
"We’re building out Azure as the world’s computer.”
-- Satya Nadella, CEO of Microsoft Corporation, in his ”Vision Keynote” at the Microsoft Build 2019 Conference
This is where this all is headed. Right now, they're all building the back-end infrastructure so that it is ready when the telcos have finished upgrading their (mobile) networks to make the necessary bandwidth available. What will feel completely natural to use in five years from now, is being built today.
But all of us should ask ourselves the very important question whether we want this future.
Here is the must-read book on the topic, and it explains in non-technical language why that question is to important:
"The Age Of Surveillance Capitalism"