Today's graphics capabilities and therefore game physics capabilities are really wild but also there are trade-offs with 3D gaming and little nuances of the physics can creep into gameplay and cause issues. Having a character get stuck on a small step or rock or whatever leftover physics model can be really frustrating. That mostly didn't exist in old school 2D games, from what I recall.

The mechanics were much simpler but also didn't have massive room for errors/odd conditions to manifest like modern games.