I build 3D models for scenes of stuff like rooms with furniture. There's just no way I could make them look decent and consistent and build interesting shot compositions while also keeping to a decent update schedule otherwise. It still takes a bunch of work, like I still need to carefully plan the layout of my room and change it from a cold, unlit 3D model to a convincing environment with texture, fabrics, different materials and add in my characters with consistent perspective, so I don't consider it cheating in any way, just a handy tool.
I don't think it's cheating or anything to use 3D models for figures, but I do think that it has a tendency to make poses feel really stiff and weightless if you don't use them together with a decent understanding of anatomy and stuff. It's no different really than how rotoscoping in animation can come out great or awful depending on how the reference was used.
Overall, I have infinitely more respect for people who use 3D resources and create a unique comic with that little helping hand than for anyone who traces or copies the work of other artists. It's a handy resource that steals from nobody and helps when people expect such high quality with such high turnaround these days.