I don't consider myself deliberately "estranged" from wider family or anything of that nature.
I've never been particularly close with them at any point, and I'm not particularly interested in them or bothered by not seeing them.
I have plenty of friends and acquaintances who are not family or related in any way, so I don't feel like I'm missing anything.
The reason I choose to avoid family gatherings and don't attend weddings, funerals and so on is quite simple. My dislike for children and wish to avoid them is so strong that I opt out, rather than turning up anyway and laying down demands that people leave their children out, or at least keep them away from me, which I think would be an order of magnitude more unreasonable, entitled, and ridiculous than simply opting not to attend.
For the same reason, when I'm in a public space and there are children present, if it gets to the stage where they are irritating me, I simply leave. I'd never dream of having a go at adults/parents because of children's behaviours, because I completely understand they are just children being children and the "problem" lies entirely with me, but again, I'm not going to fake being interested or liking them, or force myself to tolerate them just because most people are absolutely fine with them. I don't have to be fine with them. I have that choice.