I've used Cygwin X and Xming before WSL even existed.
The beauty of X410 is that you click "Install" in the store (which also means it auto-updates), run it, and that's it - it's configured out of the box to work in desktop integration mode. Top-level windows are projected onto the host desktop, clipboard is shared etc. It also has some convenience stuff, like DPI scaling.
I don't think I'd have paid $50 for that myself, to be honest (although I don't think they are actually selling it at $50... this looks more like one of those "permanently on sale" psychological tricks). But when they just got started and were selling it for cheap? I think it was a bargain then. OTOH for somebody who has never even seen an X server before, I can see how it can be a bargain even now.
That's Cygwin, not WSL. I don't think those two are compatible. I think people want the actual Linux you can get with WSL, not a pseudo-Linux like Cygwin.
It doesn't matter what X server you are running. It is a server, you can send data to it, and it will render the windows. In this case you tell WSL to use X server on Windows and it will work.
I think I used Xming for this purpose before.
You can also render windows on other computers if network is open and access is provided.
Cygwin consists of ordinary Windows programs, WSL2 is a specialized virtual machine: they are partly redundant (for the purpose of offering well-behaved POSIX tools) but perfectly compatible.
This would be a correct comment in other contexts but you seem to be unaware of the architecture of X. You can run an X server under cygwin and X clients under WSL.
The beauty of X410 is that you click "Install" in the store (which also means it auto-updates), run it, and that's it - it's configured out of the box to work in desktop integration mode. Top-level windows are projected onto the host desktop, clipboard is shared etc. It also has some convenience stuff, like DPI scaling.
I don't think I'd have paid $50 for that myself, to be honest (although I don't think they are actually selling it at $50... this looks more like one of those "permanently on sale" psychological tricks). But when they just got started and were selling it for cheap? I think it was a bargain then. OTOH for somebody who has never even seen an X server before, I can see how it can be a bargain even now.