Interesting...I've got an old 2003 rv rental, and 2013 Arctic Fox, both 30 amp.
2003 X-rental still has original elec cord and plug. Who knows how many times the rental has been used and abused. The 2013 Arctic Fox I've replaced plug twice now. Cord and plug on the rental looks like couple mils thicker and bigger wire size. Last time I replaced plug on trailer I looked at the rental cord and can't find name, only a stamping in rubber of a corp seal.
RV OEM's found a way for their product to last through their warranty period at a cheaper price I guess.