I wonder, how often do you have a talk with your son in which he hears only praise and acceptance? Please do not misunderstand me. I have four children, and they know that I do not shy away from reprimanding them verbally or with stronger consequences. And I know that sometimes even the most positive and encouraging parent has a kid that just does not seem to respond. So I am not trying to put this on you.
I commend you for pushing him out of his comfort zone, especially in getting away from electronics and out into the real world, to interact with people. But just in case this is a factor, I am encouraging you to add a positive encouragement factor to the other answers you get here. The next time you talk to your son, say to him "son, you are so smart. You are always getting good grades, and I really appreciate that I don't have to worry about that," and give him a hug. Nothing else - no "if only...." or "but ...". Do not turn it into an excuse to get in an item of correction.
In fact, if your interactions with him have been mostly negative for a while, for the next several days, even a week, do not allow yourself to correct him on anything, only to give him praise, encouragement, and acceptance. Tell him you love him, you think he is awesome, and you appreciate his grades and anything else you can think of that is positive. Invite him out to get ice-cream, and do not say anything unless it is recalling a funny incident between you two, or talking about plans for christmas, or what he wants for a gift. And if he says a new game console, resist the temptation to criticize his addiction to electronics. Only, when you invite him out, just you and him, it is ok to ask him to leave his phone or tablet behind at home, tell him he can get back to it as soon as you get back home, and that it will only be a little while.
The thing is, if you do this, your son will start becoming addicted to your attention and approval. More than just fearing your correction or your taking away his electronics, he will start getting hooked on those words of praise. This is a much more powerful motivator than fear or yelling matches.
When I talk to my kids, I can see that they hang on my every word. When I correct them for something they have done wrong, I can see they take it deep into their heart. But I am sure that is because their heart is completely open to me. They want to hear from me, and take in what I say, because they know nine times out of ten, that will be words of appreciation and acceptance. Not a day goes by that I do not tell them I love them, I think they are awesome, and I appreciate specific good things I see in them. I look for their gifts and express my amazement at them.
My one son (I have three daughters also) is the poster child for strong willed kids. I have read books on strong willed children, and the examples they give are nothing compared to the examples I have from my kid. My son makes those kids look like compliant pansies. But I have taken that strength of will as a neutral thing and encouraged him about it. Showing him how there are good things, very important things in life to be stubborn about, and how great men always tend to be very stubborn men - only they learn how to be stubborn in a kind way and what things are worthwhile being stubborn about. He is also very smart and gets straight A's. He has a girlfriend and some good friends at school. Enjoys video games more than I would like, but is also constantly reading books (the old kind - made of paper). Today we received yet more recruitment letters from Stanford and Vanderbilt. I love to brag on my boy. But here is the thing. A couple of weeks back, on the way home from school, my son told me I was his best friend. Unless you are a dad and have heard your son say that to you, you cannot know how that feels. To know that your awesomely smart, and awesomely stubborn son looks at you and thinks you are his best pal.
But, you only get that if your child knows that you are his biggest fan, his best advocate. If he needed a recommendation from someone in his family, if you are the first person he would immediately think of. If the moment he sees you, he thinks (even subconsciously) "I am about to get some love". Then, your son will be moldable to you. Otherwise, it will be difficult for you to redirect his personality, and any correction will be liable to be undone the minute he is out of your sight. That is the other thing about a child being addicted to your love, praise and approval - it works even when you are not around.