I love Godot but it's not a particularly brilliant example of what you are trying to say. Many games made with Godot generate more profit than the entire budget of the engine itself.

The engine itself is far from cutting edge and missing several features that are now quite common elsewhere, like texture streaming, bindless textures, etc. The speed of development isn't blazing fast either (see the implementation of the traits system). Devs are excellent at what they do but one could wonder how much faster and further it could go with more fundings.