Since Godot is open source - it will probably never have a fee. Whether you should switch is entirely up to you. I would definitely suggest to at least give Godot a try (a week, maybe two) and see if you like the scene/node paradigm. Two years of Unity is enough to get to a point where something starts annoying you (e.g. we've been waiting for nested prefabs for years). But, don't force yourself. I had good reasons and I don't regret doing it. Who knows, I might go back to Unity if professional (9 - 17h) work requires me to.