Take Xin Yun as an example, even if he never came here, he could learn to fly using his wings, but it would be very difficult for him to truly tap into the potential of his wings. This is just like the sprinters on Earth who, even though they can run without formal training, can run much faster once they have undergone proper coaching!
In fact, science has proven that with the right training methods and the right way to run, everyone can reach a higher level, approach, or even surpass the limits of the human body, something that's quite hard to achieve without formal training.
Without training, perhaps Xin Yun would only ever be able to utilize 50% of his wings' capability, but once he underwent training, he would at the very least be able to exercise 100% of his own strength, and with continuous training, he might even reach 120%, or even 200% of his capacity.
