I don't see it as avoidant or anti social. I like to talk to people in person or hear their voices. I'm not even big on texting either.
I value my privacy, people don't need to know everything going on in my life. The people I value, I keep in touch with and vice versa. Sure I've missed out on connections and events, but

. I think social media is too intrusive. I also find it interesting that the more we are connected the more we seem disconnected. I hate that I go out and everyone is stuck on their phone. It's everywhere. Entire families out, children ignored, and the parents are stuck on social media.
It's sad. Yes it can be used in moderation but it's not for me. I had a MySpace in high school and deleted it then too. And no, I wasn't some social pariah. I was fairly popular...
I also HATE when I go out with people and they're constantly snapping pictures and are on their phones. Me not having social media makes it easier for me to avoid these people. I just want people to know me and not a facade. I think it's easy to get sucked into it. I can make a page and have you thinking I was jet setting and living a super dope life. The truth is, I'm broke, in school, shop at the thrift store, and am cheap as hell. But I travel for the low, stay in hostels, eat good food, and have decent clothes (used)...so yeah lol.
I firmly believe there are people you weren't meant to keep in touch with, they're fairweathers. I keep them that way. I see social medias value dependent on your industry, but I'm not in those industries.
Also I hate taking pictures of myself.