I said "hoe," wow. I meant "How..."
One long, continuous round would lead to death or slopfests. Boxing cut back from 15 rounds to 12 back in the 1980's because guys were getting hurt and killed in later rounds. The old "no time limits" UFC/Vale Tudo fights had several instances of guys just sitting in each others' guard throwing tiny, negligible shots for dozens of minutes at a time; imagine Jon Fitch being able to blanket someone for as long as he wanted. As for corners, I don't know how "necessary" they are, but they make for better fights by getting fighters refocused and by acting as their eyes and brain during the fight. Fighters perform better with a corner, at least when they listen to them.
legit rules: no eye poking, no fishhooks, no biting, no nuts hitting, no cage grabbing, no hitting the head of a grounded opponent, no weighclasses. fights made on the right type of stylistically type of fight with good matchups. Anderson Silva can fight McGregor and Alistair Overreem because good matchups. Weightclasses are stupid because fighters have to diet when they shouldn't.