Godot has almost doubled how much money it gets from the community: https://fund.godotengine.org/ (though that sum should probably be much, much higher)
Sadly, those figures are for perhaps the most popular open source engine that's friendly to indie developers, which means that other engine developers really can't count on much funding at all being there. Reminds me of: https://staltz.com/software-below-the-poverty-line.html