Why is a separate /boot partition needed?

I was wondering this too! I was checking on FreeBSD and only had /boot/efi and remembered I just installed F43 beta with /boot/efi: New user : installer feedback - #36 by Espionage724

But figured that can’t be where things are stored (FreeBSD only has 1.3MB usage there :stuck_out_tongue:). But if /boot can be on the same drive as /, I wonder why separate partitions is default?

I guess it gets into subvolumes and separate /home stuff as a benefit, but the simple traditional large / avoids tiny /boot issues :stuck_out_tongue: