Been at this hobby off and on for about 50 years, as a teen I remember that our Camper had a spare. My first two MHs I owned as an adult had a spare. My newest MH, a Diesel Pusher did not come with a spare or a place to carry it. Some people opt to carry a tire only in one of the bays. I decided I wanted to carry a spare tire that was ready to go. Yes I have ERS and a Credit Card, but the ERS may not have access to a spare that will fit or match and it most likely will if available at all be at list or more. Further the last time I needed a spare it took over 4 hours to get road service out to me and that was only because I had a spare. If I had to get a tire it would have been the next day at best. I have a mounted spare on a Roadmaster (Simpson) carrier AND I have the tools to change it if necessary. As you might guess I fall firmly in the have it with you ready to go camp.