I get more than enough social time from my partner and a small handful of friends that I see on occasion. I lived quite a full social life, with a huge variety of people and activities, yet surprisingly I don’t find it all that memorable or important in retrospect. It’s a similar feeling to looking back on one of my former careers.
Introversion can be a byproduct of so many different things that saying “it’s just a label” is not only absurd by itself, but utterly disrespectful too. It can be a choice too, sure, but that’s not the case for quite a lot of people.
We should take every opportunity to make life as fulfilling as possible, even if we don't always succeed due to things outside of our control. (Note: this is an abstract claim for what you want, I'm not saying being extroverted is more fulfilling than being an introvert.)
I do care about what values, passions and friends I have, and I have tried to find a set that is consistent.
I do not mind if someone tells me "I am an introvert", even if I do not find it extremely interesting. But if he says "I am introvert and will be unhappy all my life because I can't change that", I can't avoid thinking that he is focusing on something that does not help.
Certainly, what you find comfortable is somewhat choosey. Over time it changes and evolves, from your own experiences. The more you do things, the easier and more comfortable they become.