Your child is not a nice person, and is probably going to be as much of a failure at life as his father. Unfortunately, this is because you are truly awful parents. His dad is just an all round useless person so I guess there's not much there that you can do about that. But you are a terrible parent too. I don't mean abusive or mean, just bad. You love him, but you are too selfish and too lazy to do the things that he actually needs and that has, sadly, been true from day 1. You are frustrated that he has no friends and his teachers don't like him and you're right - they should be helping him more. But I bet they're as exhausted as I am from trying to raise issues with you only to get defensive, aggressive responses. You don't want to hear it. I understand that. No one wants to hear they're a bad parent or that they've failed their kid. But you have.
He has almost none of the skills he should have for his age, his social skills are awful, he's spoiled and rude. Ironically, the rest of us see how his behaviour is rude and inappropriate, you see it as confidence. You can't even see when he behaves poorly, never mind manage it or teach him. And when he says and does things that highlight the problem and gets pushback from other adults or children, you blame everyone else.
He probably has some ND, which is making all of this worse. But again, you didn't want to hear it. And now you're finally thinking about it, but if and when you finally actually get him diagnosed, I guarantee you're not going to take on board any of the advice they provide on parenting a child like this. Instead, you're going to continue to take the easier road for yourself and simply use the ND as an excuse for why you can't do more, or why he can't be more. So he'll continue to get no guidance, and will become ever more isolated from his peers (until, most likely, he lands up in one of those groups of problem children that you love to rant about on social media).
I know that I am being hugely judgemental, but part of it is guilt that I didn't find a way to intervene earlier. I still don't know how to intervene. I'm pretty sure that nothing your'e doing would reach the level at which social services would get involved. But I know the truth. I suspect the school knows the truth. I'm starting to think your broader family and even some of your friends know the truth. Pity it doesn't help your son.