Well, I do not agree, that Blender has less function than say Maya, Z-Brush, Unreal Engine, etc. But I have heard, that Blender optimizes their code and also, that they clean up old code, that is no longer being used. Some of the other softwares apparently doesn’t do that, so they get larger and larger.
This will probably not be the only thing that makes them so ‘clunky’, but I do not know enough to tell you what exactly makes Blender so small in size, considering what it can do.
