Mere repetition of the same actions over and over is not a way to reach mastery of a skill. Repetition with the intent of mastery requires focus on it.
Once you reach mastery and no teacher or resource available can readily help you get better, teaching others provides the best path to improvement.
Mastery is not a goal, but a starting point. There is no maximum possible mastery of a skill. There is however - and sadly - a practical peak.
Once you reach the practical peak only research, thinking out of the box and learning from new found masters, often in other disciplines, is the way to improvement.
It is an arduous and slow process, but it is the only process that will bring you to be remembered for your skills.