In 40 plus years of fitting brake discs & pads on a multitude of cars I have never come across a warped brake disc I have seen badly worn pads & scored discs
To warp a disc is a case of metal to metal friction so its the owner/driver who is at fault & not the components as they are made to exacting standards due to the fact the public safety depends on the stopping power of a vehicle & as the ratio of braking power is 80% front loading & 20% rear its obvious the front discs are going to be the ones taking most of the force so manufacturers are not allowed to diversify any metallurgical composition alterations to their products which must conform to the industries ISO safety standards
How do you explain something like the video I posted above?
Lots of different companies make the discs for the same cars. If they were all made to the exact same specification and standards why are so many people convinced one brake disc is better than the next brand?
The quality of metals varies and even ones made to the exact same specification coming from the same supplier. The same material from a different supplier can be completely different and behave very differently. It's not that irregular to find that materials that have passed stringent tests aren't the spec they should be. Extreme faults are rarer.
Many things you'll buy are made to ISO standards. They still go wrong or aren't what they are supposed to be. I don't imagine that brake discs made in the usual cheap countries are manufactured to standards you'd hope.
A lot of people say warping doesn't happen. A lot of people argue the opposite. There is plenty of examples of discs being warped. People do jump the gun and blame warping for any brake faults which is wrong. That seems to strengthen the case that discs don't warp. However, there is plenty of genuine examples of discs warping.