I think you're starting from a faulty presumption: that you NEED a belt to be a powerlifter.
You don't.
They might help a lifter push that much harder once your form starts to break, but the question is: do you really want to push past the limit of your body's ability to brace?
If you're competing with lifts where you know your going to compromise your bracing at some point in either a deadlift or squat, then a belt can help maintain a degree of thoracic pressure over unbelted. But that is way up the intensity scale to where you should be training on a day-in, day-out basis. IMHO.
Training with a belt is less about requiring the belt to train and more about being comfortable with the belt. You dont just want to throw it on when your at your limit at a meet.
I am happy to do unbelted training but with a long term goal of giong to meets I need to be comfortable in a belt while lifting, this will only come with extra practice. Also making sure that form is not impacted by the wearing of a belt is also important. Its pointless to put the belt on to gain an extra few KG if the belt pulls your form out - or more likely in my case highlights issues that are less easily seen sans belt.
There is also the argument that you can push your core harder with a belt as well so your actually training harder with one on but thats a whole other discussion.
The focus for my unbelted training has been to improve my core strength which i have been doing, but i also know that with wearing a belt i can maintain form, brace more effectively and add kg's to the lift due to this improved bracing.
I was never saying that a belt is a prerequisite to powerlifting, "a belt is a posative advantage for competing in powerlifting and is not something that should be thrown on just before max efforts" is probably a better way of putting it.
Far from starting from a faulty presumption.