Main reason being that Unity starts making you pay up if your game becomes profitable enough.
They're introducing a "Runtime Fee" on top of making you pay for "Unity Pro".
It's likely that these practices might become increasingly predatory.
Godot is open source, meaning that I won't be at the mercy of any corporation for making games with it.
I personally prefer engines that are easy to use.
It makes coding and debugging less of a headache so I can focus more on the game design itself.
I think before Godot became more mainstream,
Unity was one of the easiest 3D game engines with decent power under the hood.
Godot may not be as powerful or convenient,
but it's definitely getting there.
Though I really do dislike that gdscript is required for many things.