I wonder why more computers don't use the simple boot model that devices like the Raspberry Pi use. From what I've heard, the RPi is effectively immune from persistent malware. Firmware can't be modified [1], and while the second stage bootloader can be flashed in the RPi 4, the first stage bootloader can't be modified [2]. What this basically means is that no matter what infects your pi, you can always just replace the SD card and restore it to a clean state. In contrast, I've heard so much news about how USB firmware can get reprogrammed [3], how PC malware can survive BIOS reflashing [4], how malware can live in external drive firmware, etc. Of course, if there's a bug in the raspi firmware, it also can't be fixed, but the attack surface is so small I'm willing to make the trade-off (and buy a new pi if it comes to light).

[1]: https://raspberrypi.stackexchange.com/questions/8963/are-the...

[2]: https://www.raspberrypi.com/documentation/computers/raspberr...

[3]: https://security.stackexchange.com/questions/97246/badusb-wh...

[4]: https://security.stackexchange.com/questions/44750/malware-t...