Look, as far as I'm concerned and as an SRE, server-side Windows is legacy. (With the only already mentioned exceptions being AD and Exchange.) And client-side Windows is ... well something I don't use personally anyways.
Yep, likewise. I think the only thing that required the Desktop Experience off the top of my head was WSUS, but we have all sorts of other roles running on Server Core without any issues at all.
Sure you can, and what's the value added compared to any Linux? The joy of having to deal with CALs and licensing audits? If you just like writing cheques, RedHat is an option.
Bottom line is, legacy stuff gonna legacy.