What most of us wants with the resting system is some kind of challenge.
They could restrict food availability at higher difficulties or as a separate toggle in the options for people who like that.
For myself I play casters because I like casting spells, and I find it boring to be stuck with using a crossbow or similar on a caster. So, the current normal difficulty with lots of food available works well for me.
The more I think about it, the more I think Larian already found "a part" of the solution.
But in my opinion it shouldn't depend the difficulty level at all, it should be a core feature of the game as it is in DnD (time in DnD, food in BG3).
That said, it seems extremely hard to balance especially considering the number of items considered as "food supply" you can find absolutely everywhere.
Of course you should be able to play as you will. That's why you should always be able to buy tons of supply bags to store them at camp
