It seems to me that experience and competence are two different things that need to be differentiated. if I fly a drone for 10 hours, I have 10 hours experience. How much competence do I have? That's an open question. I think experience can be quantified pretty easily while competence is tougher to assign a number. Some performance based criteria are necessary for quantifying competence. But experience, I think, is just time put in.
So the OP's question could perhaps be restated as, "how much experience is necessary to develop competence?" And, the answer, is "it all depends."
Motivation, type of experience, recency of experience, breadth of experience, repetition of skills, performance under varied circumstances, motor coordination, patience, risk aversion, inquisitiveness, expert instruction, feedback, and a host of other factors can all play a role in how experience translates into competence. if I repeatedly take off, hover until my battery gets low, and land for a total in-air time of 10 hours, I have 10 hours of of flight experience but very limited competence in the wide range of skills that are a part of drone flying. Someone who has hundreds of hours "flying" on a simulator and a couple of hours of actual flight would have only a fifth as much actual flight experience but might be far more competent. That is, given a set of flight tasks (e.g., flight control, obstacle avoidance, maneuverability, etc.), they might far outperform me. In this imaginary situation, I have more experience but the other gal or guy has more competence.
Under normal circumstances, competence will grow with experience. But they're not literlly the same thing.