What facts? Genuinely curious. Microsoft Software in general is pretty bad when it comes to found and or exploited security problems.
I admit with all the legacy compatibility it must be hard to maintain Windows, but other projects manage that better.

This is no proof, but a data point: https://www.cvedetails.com/top-50-vendors.php

Thanks. That was a good one. Maybe compared to what Cisco does they are passable.

Yes. That’s why I use Win7 for legacy stuff and Linux for everything else. On Win7 it was still easy to deactivate (disable a few Tasks and a few checkboxes). Since the updates stopped that PC is super stable too.

_{no need to lecture me about muh sEcuRitY uPdAtEs. I know. As if any Microsoft Software was ever secure.}

Of course it can. What did you expect?

https://doomwiki.org/wiki/Doom_UEFI

Depends on the version. All of them (the newer ones with networking) have TFTP. Some even have HTTPS. I think HP Servers even have HTTPS-Boot with client TLS certificates.
None of it works with Wifi though. iPXE has wifi support for some devices but you obviously can’t start it over the Internet. You need to flash a ROM you don’t need or use a USB drive to load it. Then you can boot Linux from the Internet. (That also works if you don’t have a UEFI Shell in BIOS). https://netboot.xyz can also boot other OSes than Arch.