alternative to the volume.key in /boot for disk encryption?

[herenti]

the void linux handbook for luks disk encryption has me use a volume.key in /boot to avoid having to type the luks password twice on startup. isn't this volume.key accessible to anyone who can access my physical device and super insecure? i would rather not leave the keys to my vehicle on the roof when i walk away from it. is there another way to avoid entering the password twice because it is a bit of a pain. unless i am wrong and this volume.key is not accessible?
EDIT: it seems i did not know that /boot is encrypted and safe while /boot/efi is not encrypted. that appears to be my confusion.