The other thing is that browsers need GPUs as well. A lot of stuff is hardware accelerated in Browsers these days. Just a bunch of vcpus does not help that much.
As it is, the target audience seems to be people with too much money and yet with a shitty laptop unable to run a browser properly. I'm sure these people exist but it does not sound like a great market opportunity.
Also, from a security point of view, I don't think that a lot of Fortune 500 companies would ever agree tot this.
However, that oddly might be the path to success for this company as well: play the security angle rather than the performance angle: lots of companies worry about their employees having their laptops and phones stolen. The less data is on these devices; the better. But it will need to be iron clad and more than "We won't look! We promise". That in itself basically just screams "but we could if we wanted to". But if you think about it, a lot of office workers access internal tools almost exclusively through browsers these days anyway and most of that stuff is cloud based anyway. It's just that the terms of use, SLAs, etc. give IT departments enough warm fuzzy feelings that they don't forbid this. Office 365 is a good example. Hosts a lot of very confidential information in a lot of companies. So not a strange thought to narrow the surface between the user and that to just a remotely running browser.
Also there's the convenience angle. A lot of developers are running their development tools remotely. Github is pushing e.g. code spaces. VS code can mount things over ssh. It's becoming normal to do that. So why not do that for other things as well? Streaming games is another good example. I would not be surprised to see Google go there eventually.