For most current pro CAD, certainly there are a lot of calls to Win32 libraries on Windows, but those aren't fundamentally needed by a CAD system. There was professional 3D CAD before Windows.
I don't know what native hardware would be needed that isn't already accessible through current Chrome?
There certainly are optimisations that aren’t possible in web browsers today. Arbitrary wasm memory constraints and difficulties around cpu multithreading or simd for example. But CUDA kernels aren’t a realistic option for most cad software.
On the performance end, the is a wide range of CAD that was done on systems more than 10x slower, so that also may not be a deal-breaker. For the simpler end of professional CAD operation, I haven't noticed any performance gain from a 2nd get Core i7 to a 10th gen. On the high-complexity end, there is some benefit for some operations, but certainly there is a wide scope of application that could be fine with only 10% of peak performance on newer work stations.
The original comment was about (mis)using the browser as some kind of platform independent runtime environment for apps.
Admittedly, at my workplace, I created a few (very simple) html/javascript based apps to get some tasks done quickly (like sorting some tables, or a little task planer tool) as it is convenient, because a browser is something you have everywhere.