Perspective shift. If you think BG1 and 2, the resting system was actually very similar to BG3. It might not seem like it at first, but think about it.
1. You could rest at any time, even if it didn't really make sense.
You also have to consider the vast differences in mechanics and design philosophy between the 2 systems. In 5e, certain classes are short-rest classes and others are long rest classes; the game is designed and classes are balanced around assuming enough encounters for 2-4 short rests per long rest. Whereas 2e has no "short rests", and all classes got less resources so it makes sense to rest more often. A level-3 Wizard in 2e has 3 total spell slots per day, and no cantrips. Whereas in 5e, a level-3 Wizard has 6 spell slots per day and cantrips, so they can remain effective combatants for longer. But if they can use all their slots in the same combat...
