Very good point on packed volume.

I started with closed cell foam half a century ago for camping, switched to self inflating pads about a quarter century ago for the comfort when camping. Then a bit over a decade ago bought an air mattress without foam because it fits in a pannier better. At that time, the packed volume was the only reason that I bought an air mattress, it was even slightly heavier than my self inflating pad. Kept using the self inflated pad for backpacking and canoeing. But in the past couple years stopped using the self inflating pads for non-cycling trips and switched to air mattress for comfort.

The only time that I used a closed cell foam pad for the past couple decades was for snow camping, put that under my other pad or air mattress for insulation.

Vast majority of my camping is in areas without thorns, thus I have not had to worry too much about ground sheets or putting a foam pad under the air-tight pad/mattress. I did a week long van supported trip with ACA in West Texas a few years ago, they specifically recommended a foam pad under any air mattresses due to thorns. I rolled the dice and did not bring one, did not have a puncture but I was very careful when setting up my tent and packing it later.