No, if he wants to be a replacement, one has to assume he wants to be compatible and keep using the applications he currently uses. Any non-Mac system might be an "alternative" but not a "replacement".

$2k buys a lot of applications

The problem is with changing the software environment. Most applications are not available on all operation systems. So your hunt starts for solutions where the application is not available on other operation systems.

It's not just applications, it's time.

I'm in the middle of producing a 17 song concept album. If I switch platforms, I have to completely redo all my mixes and learn a whole lot of new tooling. What's the cost of that? Dozens of hours of my time...

But it won't buy the magical ability for a built PC to run macOS. I don't care about the applications, I care about the underlying OS

No, that was exactly their point.

You responded to a different point.