Most athletes in the sport walk around with a natural weight very close to their fighting weight. Cutting like that only really happens when jumping up or down a weight class.
Most fighters stay in fighting shape and only ever have to drop a few pounds or nothing at all for fights.
The weigh ins are to make sure no one is severely over the limit and a fight can be called off or a percentage of their money from the fight is given to the other fighter who made weight.
Also short notice fights can happen where the fighter isn’t in shape or they're taking a weight class fight that isn’t their norm and then they have to cut the weight in a short amount of time and that’s the fastest way to do.
They will then rehydrate and such after the weigh in because there’s usually an allotted allowance they’re allowed to be over once the weigh in has happened. It’s usually not much a few pounds since the weigh in is normally the day before so they only have the rest of that day and the morning before to do such.
MC is like a passive doll and has no real personality or sense of self.
Side note - for anyone who like knows the sport, I get the idea is that you lose the water weight to weigh in, then put it back on before the fight. But it seems...not stupid - like redundant? I understand it can be done safely, but idk doesn't seem to be in the best interest of the athlete and creates a system where everyone has to do it. Why don't people just fight in a specific weight class and ban the dehydration thing. Or safely lose the weight - surely being that big you're required to sustain a huge calorie intake, that could be cut down - but maybe that sacrifices strength? idk. Can someone with a more nuanced understanding explain why it's done and kept around?