RV refigerators life span?????????

I saw a post a couple of years ago about the chemical they use is caustic and erodes the metal tubing they use in the fridge which causes the tubing to fail. If that chemical is flamable it explains the problem.

FWIW my last trailer went 10yr before it rusted out near the burner. Was mostly used on gas

Probably, but I think the lifespans are all over the place. IMHO they work till they fail.