Honestly… The only reason people use belts is that they are afraid of damaging their spine or whatever… It might have actually come from a past injury, or some sort of fake ass bro science which says that XYZ is dangerous for you.
Dude come on I’m like 6 feet tall, 165 pounds… At 5% body fat, and I have not even consumed protein powder in the last decade. I also weight lift barefoot, no stupid belts, because belts are just for cowards.