The alternative being running os-prober at boottime, on every boot.
Currently, we set UUID using os-prober whenever we remake grub.cfg, analogous to that would be registering web-server static IPs with a DNS, which provides the domain name aliases (we don't need to see UUID in the GRUB menu right? We see the OS names).
An analogy to the alternative would be to ask all devices on the internet to send their usage methods everytime you try to look for another site.