Thanks.
It is actually quite enjoyable programming 3D in stencyl. People take Unity and UE4 for granted since they did the background work and vector calculations. In order to program 3D in stencyl, you have to do the calculations yourself. I've done it, merrak has done, mdotedot has done it. Stencyl is not useless for 3D, you just have to put in some more time and effort.
That being said, sure if you want the background work already implemented, then unity, ue4, cryengine, lumberyard, etc., would be the way to go.