Depends who’s training, what their goals are.
Good for bodybuilders or strength oriented athletes who want to maximize the strength of their back, leg and shoulder muscles. Because they are serious enough to work with a belt, they most likely are taking into account core exercises and power work to increase abdominal strength and balance.
For the 3 times a week person going for health or weight loss? Definitely not. They will not have the strength or endurance to put up heavy loads of weight. They will also want to engage their abdominal, obliques and back muscles to stabilize the body.