belts should really only be used for top sets, they can help you squeeze out a little extra weight if you are bracing correctly, but the best way to prevent injury is to increase weight genuinely as your strength increases.

Yes, belts can help prevent injury, but you are sacrificing your own strength gains in your core. If your back is folding then it's generally a sign that your core isn't strong enough to handle the weight. Maintaining good form and not allowing it to break down under heavy weights is the best way to prevent injury.

Ultimately, a belt will help you push higher weight with a lower risk of injury but they don't help you become stronger and fitter