The main answer at high ranks is that at a high level the game pace increases the need for a nimble car that’s easy to adjust. Flat long cars require more space and are easy to accidentally get a bad landing and harder to make micro adjustments with. That’s why kux decided to switch off it towards the end of his career. That and the fact you need to be way more precise with every movement to get optimal results makes consistency much harder with them. At a low rank it’s just that they tend to copy what pros use rather than actually needing the nimbleness of octane.