I don't disagree actually maybe there is to high jump from gold to diamond. But keep in mind there are no PRO FLEX players. Its better to specialize
See i can play midlane like a challenger (hence why i reached challenger multiple times) but I can play other roles as a diamond and given taht mid is the most popular lane its a struggle to climb
I was the scarriest ADC yasuo in the world at one point one year before it became the official meta. But how would I ever join a team since by maining mid and ADC yasuo I would overlap with the ADC player (AKA my yasuo adc has no value and my ADC teammate would have to learn yasuo)