I've heard one way the difference between introvert and extrovert described is that both can do it to the same level of skill, but an introvert might find it more tiring and require some "alone time" afterwards to recharge. That would agree with my own experience.

This is correct. Being exhausted from social exchange also, quite naturally, leads to less time practising it, generally.

I also agree. I think introverted/extroverted is less about "ability" and more about "preference", while the "skill" of talking with others is something both categories of people need to learn. The introvert can for sure appear as an extrovert with training and practice, while maybe not enjoying it as much as the extrovert.

I agree. I think extraverts just typically get more practice.