Godot being FOSS is awesome, but I suspect if any project with Godot's scope and goals came along and garnered as much support as Godot (not sure how you'd do that without being FOSS but let's just posit they have FANTASTIC logo or ceo or something) would be the new hotness as unity continues to shoot itself in the face over and over again.

FOSS is real nice, but it's frosting, the cake is knowing your game engine isn't going to turn around and suddenly be an antagonist, a threat to your ability to plan projects.... you do not what your game engine to be a wildcard.

And that's unity these days.