I would say most of the time ... in the office I multitask, using both ... at home, I use either depending where I am sitting. Under none of those instances has the laptop been "on my lap". One buys a computer to fit ones needs. People however have a compelling need to put "labels" on things, and "potable desktop replacement" just doesn't work cause they don't want to use that many words. The fact that "laptop" remains in the lexicon is unusual in that, outside of planes and trains, it's rare to actually ever use it on ones lap.
A Gaming Laptop is, in essence, an oxymoron as a gaming laptop w/ any oomph will run a bit too warm for comfort on one's lap.
Among the examples would be one of our own ... We uses 17 " gaming laptops as our main tool in the field to create As-Built Drawings on construction web sites. Contrary to popular belief, peak 2D and 3D CAD performance is obtained using GTX GFX cards (not Quadro, which excels in rendering). It's used in our vehicles, it's used in office trailers, inside buildings under construction, it's used in water / wastewater and electric plants on the nearest flat surface. And as the day goes on, it may be used in a dozen different locations, some w/o power.. As opposed to an "All in One", it's also a lot easier to travel with.
As for moving to 24", I'd find that a bit unwieldy for many of the above uses, but on those site where, for example, where we had access to a 40' portable office trailer, the extra real estate (disappointed no mention of resolution) would certainly come in handy.