Need one of these.
Pintle hook.I thnk the reason some trailers come with them is that they carry a lot more weight than the average recreational vehicle will weigh. Most light duty trucks do not have the hitch carrying capicity to use one of these type hitches to it's rated capacity.
I think you will find them mostly on commercial flatbed type trailers, or trailers used to carry gravel or sand. I have never seen one on a recreational trailer.
In addition, most rental places my use that type of hitch becuase they rent large trucks that may be used to tow heavy vehicles like tractors, backhoes etc. and those trucks almost always have pintle hitches.
Barney