What if the person had a mental health issue like social anxiety, would you still want to hire them?
I have social anxiety and incredibly shy and quiet. I've been continually employed for the last 36 years and now run my own business.
I would never apply to any firm that appeared "trendy" or in any that required lots of teamwork, presentations, etc., or any of the big national firms, in the first place. I've always applied (and been generally successful) with smaller/private firms where you're more likely to be interviewed by the owner rather than a professional HR manager or be forced to engage with group interviews etc which I know damn well I'd be useless at.
Now with my own business, I have never "done" the business networking meetings, nor pitching to larger businesses. I've always been very clear in targetting similar sized, small, owner managed businesses, who, by and large, turn out very similar to me in terms of personality etc - i.e. small firms are often owned by shy/quiet kinds of people.
So, OP, try changing the kind of job/employer you're looking for. Like attracts like. You're never going to succeed as a square peg in a round hole, so target potential jobs/employers that look to be a square peg too!