The root partition ID is in the grub configuration, it’s mounted when the system boots. Then fstab is read and the other partitions are mounted.
fstab is needed for root mount options and other partitions, but as you saw with your system if the only partitions other than root are not needed to boot your system will boot fine (I don’t know which options grub uses when mounting root though)


















I’m genuinely terrified by those… Any solution to avoid them besides looking closely at everyone wearing glasses?
I know there are apps that try to detect them but I don’t want to leave Bluetooth enabled on my phone 24/7