I 100% empathize with your situation. Mine was nearly identical in my early 20s. I’m very introverted, spending time with people is draining.
In my late 20s, I started forcing myself to say yes more to nearly anything and everything. I made some great new life long friends, had experiences that I’d never had considered in the past, and overall became a better person due to more varied experiences. Additionally, I’ve had many career opportunities open up because of these relationships.
Trust me, I know the comfort zone is easy to stay in and enjoy all the time. I do it still! But I also try to force myself out of my comfort zone. It makes me a better person with more perspectives to draw upon.
Finally, drinking doesn’t have to be the activity, that was a quick example. Going to the beach, go for a hike, go to an arcade or barcade, play board games, and on and on.
And if you don’t want to, that’s perfectly fine. But I’d highly suggest just trying it for a period of time. You may dislike it at first, but it will affect you as a person in many ways, some of those may be positive.