Many of the other comments on this post are misinformed and based on past versions of Godot. But Godot has recently had an update that has focused primarily on improving it's 3D support. I get the impression that many people looked into Godot version 3.x, and never bothered to look any further. It's true that it's not as mature as Unity, but that takes time and it will eventually get there. But people are unfairly disregarding, at the moment based on past versions being focused on excellent 2D support but mediocre 3D support.