Even if you don't expect EULA to be enforced (will you pay for my lawyers/fine if it is?), you still need a copy of the system which you can't buy directly. You're left with unauthorised copies if you don't have any MacOS hardware and the same question - would you cover my legal costs?
How do you legally download Big Sur without having an existing Mac machine? I thought that option was gone for some time now. A quick search doesn't bring up good solutions.
On the flip side, why would it be legal? It's looks like a pretty cut case of copyright infringement. It's their software, you're not authorized to use it, but you're using it anyways.