Support and comfort — nothing else beats them. Also, it is the closest one can get to going “commando” but still have support. Finally, why would one be ok with men wearing a jock strap or going “commando,” but have a problem with men wearing a thong (which were originally invented for men)? I don’t get it.
When they wear other things over it it’s OK but men on the beach with bellies so big you don’t see them wearing one until they turn around is just…no.