Sometimes its better to accept things and work on moving forward instead of questioning why we suffer from certain symptoms.
I think that's true to a point. It's helpful to gain awareness, because it helps us know what we might work on accepting, vs what we might work on changing. But sometimes we can meddle in our heads for years about the "why" and not do anything in the present to simply change a bit. I noticed this most with my alcoholism (WHY was I an alcoholic and could not drink normally, no matter how hard I tried? I actually had to just stop drinking or die...they "why" started to make sense many years later).
That being said, early connections do play a pretty strong role in how we connect to others. But so does our personality. I'm introverted (personality) but I'm also very avoidant (early trauma and also attachment issues). I can actually work around both, to a degree. It helps me to know that I will NEVER be the person who enjoys loud gatherings. It doesn't mean there is something wrong with me. I can do them if it feels important (like a very special event for a friend who wanted to invite 50 people into a small space), but I will have an exit plan and probably leave first. But I can challenge myself to just be around people I generally feel okay with more. I have adapted very strongly to avoidance and isolation, so often I don't even care to push myself. I'm busy with all my little solitary projects.
Do you ruminate over what others will think of you? Do you have fears of rejection or feel like you have to feel a certain level of confidence before jumping into a group, like you will be accepted by at least a couple people? Is it easier when someone you know well is present? Or when there is a goal or focus, such as a book study or support group? I ask because these kinds of things matter to me. Find what kind of socializing feels okay to you but also work on what might be ruminating or cognitive distortions (like "nobody will ever like me"...or whatever they are for you). Challenge yourself with the settings which feel somewhat manageable, even if they don't look like what everyone else is doing. I really love my AA group for the structure but also the chance to feel closer to others and give and receive support.
If you really want to understand more, you could look into adult attachment styles (or childhood...there is overlap). I'm mostly avoidant but with some strong tendencies towards disorganized attachment with people I get closer to....so avoidance keeps me far away, and as I get closer I get disorganized. I recognize my tendency to confuse people this way (I show up, act connected for weeks, then disappear without a hint as to why). But mainly consider what feels right for you and decide on one or two goals, maybe even just for this week. One friend you can call for a walk? A familiar coffee shop where it feels semi-okay to bring a book and be around new people? A support group or a class involving a topic you are interested in?