I am sure this is obvious and I am just not in the right ecosystem to appreciate the problem, but why do they have to include a Linux emulator to use Wine? Can't I just run Wine?
To run win32 applications inside Windows operating systems that are too modern (e.g. for 16bit apps), in a browser or on macOS (recent versions of macOS do not have 32bit support and IIRC runnin 32bit wine was not easy).
Of course these are my guesses, I don't think the "purpose" of boxedwine is ever explicitly stated.
Oh oh oh! It in fact now does feel pretty obvious: I missed the part about how if you have this entire stack as one piece you can run it in the browser. Thanks!!