Yes my understanding is 2D is first class while in the U engines you tend to turn a 3D scene sideways to get 2D and have to deal with vector mathematics rather than points in various functions. At least that's one reason a few people cited for the switch since they wanted to focus on 2D and it works without extra layers or abstraction.

As I understand it, orthogonal-view 3D as 2D is faster in the GPU than "real" 2D in the CPU, which is why it tends to be used.

My comment was more around tooling and complexity as seen by the programmer. You can have functions that look 2D but are really 3D behind the scenes, like glVertex2f in OpenGL. AFAIK Godot uses GPU acceleration still for 2D scenes like all games these days should.