That's a good point. Thinner lather is much slicker, but the tradeoff is duration. The thicker the lather, the longer it lasts. The only purpose the air bubbles serve is slowing the dehydration of the thin film of lather directly on your skin. There is always a tradeoff between slickness and lather longevity, so the thickness of the lather should match the duration of the shaving passes. ...
When I used to shave in the shower with bar soap (lathering on my cheeks with my hand) and a multi-blade disposable, there would be times when I achieved a super slick, very thin film of lather. It did dry quickly though, even in the shower. It was a rarity however(maybe I'm impatient), and something I seem to never achieve with puck soap and brush.
When I'm testing new soaps with a DE, I do an 8 pass "Konami" shave, ...
8 PASSES - HOLY CRAP!!!!!! I can't imagine running a razor blade across my face 8 times!! 3-ish times is more than enough.
As is so often said about everything around here (and it's certainly true) YMMV. I would be willing to bet that there probably isn't a lick of difference in what is being done among any of us. We're just describing it differently. Only the shaving gods really know...