The problem is unfortunately a little more complex.
You can still spam long rests quite aggressively, it just requires a whole lot of clickety-clicking and general busy-work in order to pick up all kinds of foodstuffs and pushing them to camp and then picking them up from camp in order to actually use them.
But if you don't want that chore then long rests are somewhat limited, which then becomes a problem for some of the spellcaster classes that have to pick between constantly burning spell slots due to concentration failures or simply not bothering with concentration spells.
