I agree that it's really useful to have separate piles of money reserved for various purposes, but having separate accounts for those piles seems like overkill to me.

A modern "challenger" bank (I use Monzo) will have a facility like "pots" where you can ringfence amounts which won't appear in your main balance. Monzo even has a "salary sorted" mechanism where it recognises when my salary comes in and automatically moves portions of that money into the correct pots. So, right away, I can see that any money left in my main balance isn't allocated for anything and can be used however I like.