I’ve known a couple strongmen who have worn them. I’m not sure of their reasons, but I know at least one had a history of back pain in spinal injuries so I imagine that has something to do with it. Either way, a neoprene support belt is not going to act the same way or serve the same purpose as a lifting belt. They’re very different things.
A lot of strongman guys use them. They say it helps keep their back warm but doesn’t really provide that much support. All of the guys I know that use them put the soft rehband back support on, then put their normal powerlifting belt on over it. It won’t replicate the way a normal belt performs. It is more of an add-on