As a 2D-Engine everything related to 3D should mostly be about small effects or visual fidelity, not about 3D-logic. Physics in 3D go in line with different types of collision bodies, raycasting, 3D shadows, lighting, etc. These are things that belong to a 3D-engine, which Construct 3 is not. Although it is a great engine, most developers would not develop a 2D game in the Unreal-engine. It is obviously possible, but it is clearly not made for that purpose, so a lot of things feel hacky and overcomplicated. Also, it is lacking a lot of pure 2D functionality, because - obviously - it is not the focus there. Similarily for Construct 3, if a game needs more advanced 3D logic, there comes a point where switching to a native 3D engine is just a better way to go. There are enough things that can be improved for 2D games, where the ressources are better spent, instead of extending a set of features for something that is not the main focus anyways.