I am going to challenge the theory of lightly quilted, puffy quilts being warmer too. Not in my experience. Maybe the puffy comforter style quilts stay on you in bed easier, or you prefer the lighter feel, but actual warmth? I'd want to do some scientific evaluations to see measurable difference .
It has a lot to do with what kind of batting you are using. If you like high loft, poly batting, then you will have a puffy quilt and it will be quite warm, and generally, that poly-batt is not best served with a lot of quilting. That's why people liked poly batting so much in the 70's and 80s -- freedom from quilting requirements.
But now there's a more widely-held aesthetic of quilting where the quilting is an intrinsic part of the design, and to showcase that, cotton blend, lower loft battings and finer threads work beautifully and result in warm but highly drapable quilts.
If you want a lot of poof, like a comforter, then quilt only the most minimal amount prescribed on the batting-- like 18 inches. Or tie the quilt. Replicate what you see on a store bought comforter from Ikea or Target. Usually quilters are not aiming to make comforters, though.