I think the detailed description of this vulnerability described it as non-persistent in UEFI, but that you could install something that runs before secure boot that would be persistent. I think that’s splitting hairs, though - if you’ve been compromised by someone that has the skills to pull this exploit off, then they can probably chain something else into it now that they’ve got basically bare-metal access.
You also need to have sufficiently infiltrated the target’s local network to masquerade as a PXE server, and be in a position to force a server to reboot / just wait for one to reboot. Yes, a few places have large, fairly open networks with a lot of devices configure to PXE boot and they should apply the update before the next reboot, but vast majority of people, no issue at all.
Yeah, more of a “visual novel using the ‘sims’ engine”. If you were expecting “the sims” but with medieval architecture and activities, then that’s not what this is at all.
It’s how I installed Arch btw on my desktop, tiny boot image basically downloads the installer into RAM - NetBoot.
But yeah, if you’ve got a computer that’s old enough to be fully supported yet new enough to have the UEFI for hardware, an ethernet network which is robust enough to download full system images on every restart yet simple enough for the firmware to understand, and tonnes of memory free to hold the whole OS at all times, and you can tolerate the fact that restarts take ages, then it works great.