>>3812428
>>3812450
And just to be extra clear here, 2D billboards work if they aren't that wide, since they can get away with having a cylinder collision the player can bump into. This is why the 2D billboards can work for trees or people, but not a wide fountain, buildings, the ground and so on.
Not only would a building as a 2D billboard have effctively an large invisible wall in front of the player, but it can't look identical from all angles and would look extremely strange if it rotated. Even if you used multiple billboards in a + shape. Because then something like a door would never be accessible.
This and more is why older and newer games that make heavy use of 2D billboards and such didn't do it for a lot of things like the environment or larger shapes like buildings and especially things like a castle.

This is what I'm talking about when you don't understand any of this. You're not thinking about the practical execution and implementation, only the kneejerk "that looks neat" reaction with zero thought beyond that.