Hey..
Can't speak for the masses, but I wax any part of the boat exposed to elements.
The non-skid deck surfaces do not get waxed.
My formula is wax once a month during boating season. During the off-season and between trips she is stored indoors.
I wax in the fall before winter lay-up.
We go to the Keys for part of the winter and before we leave the whole boat;inside and out, gets 2 coats of Turtle Wax Platinum Series paste wax. This includes the Yamahas and their lower units.
My Gulfstream 232 is a 2007 and it shines like new. There is the mark or scuff here-and-there, but it looks great.
Bottom line? It takes work to keep up with it. I justify it by my enjoyment of just looking at it and, let's face it, it's a major investment.