Yes - all the times I've seen PXE boot used, the usage has been "Hold F12 during boot to reformat the disk and re-install the OS from scratch"

Which is something that happens inside a trust boundary. After all, if an untrusted third party gets to install your OS it's game over, UEFI bug or not.

And consumer devices often don't have a network card - or come with PXE disabled in the BIOS.

Some thin clients boot from PXE so they can forego local storage completely. Being able to update the entire fleet and completely prevent any kind of local changes with a simple reboot is a gamechanger for maintainability: you can be 100% certain that every "installation" is absolutely identical.

It also wasn't uncommon to install a server's hypervisor to a USB flash drive, or a tiny local SSD. Server motherboards with internal USB-A ports (not headers, the entire port) were quite common, and there were even IDE flash drives you could plug straight into the motherboard. This allowed you to completely dedicate the regular storage to the client VMs. I would not be surprised if that same market also used PXE for the same reason in larger installations.