Godot recently announced that they are going to allow you to disable engine features[1].

From the announcement post:

"We got requests from single developers working on 2D games that they would like to disable the 3D editor and nodes from the Create dialog. The reasoning is that, if not in use, they just add clutter."

[1] https://godotengine.org/article/godot-32-will-allow-disablin...

Many 2D games nowadays are just 3D games using an orthogonal camera because that's still faster on the GPU than the old-school methods of sprite based rendering. I think even SDL2 uses OpenGL acceleration for its "2D" texture and render functions behind the scenes. It's mostly a distinction without a difference.

Godot's 2d engine is completely separate from 3d (unlike Unity that uses 3d engine to render 2d games). You can build export templates without 3d engine for smaller executable size. In 3.2 you will be able to disable 3d features of editor to make your workflow more streamlined.