I've been at this role for just over a year now and I've eaten lunch with my teammates maybe two or three times.
Firstly, I spend all day with these people as it is and while they are perfectly easy to get on with and have a laugh with, my lunch time is for me to eat and catch up on my reading.
I really dislike cafeterias in general. They're too noisy, bright, uncomfortable and I would much prefer to just go and eat in peace and quiet.
I've been out with these people like a dozen times for meals, nights out leaving parties etc. but once or twice a week? That's way too much. I have things I like to do in the evenings, like exercising, playing learning guitar or improving my development skills. I also have a partner I wish not to neglect.
I'm totally fine keeping my work and colleagues separate from the rest of my life.