I have also been fired a bunch of times, and people describe interacting with me in the exact same way as you just described it.
Your brother is consistently going for the wrong kind of job, from the sound of it. Operations jobs.
I eventually succeeded when I switched to work that is more strategic and creative.
I got really into language learning, blogging, website building, and then just followed things forward.
I then eventually became head of marketing for two different startups.
And now I run a bootstrapped company that is exploding in growth. We’ll probably do $10m+ next year in revenue.
I pay people to take care of details while constantly explaining to them what my vision is.
I KNOW the feeling when you see people lose faith in you. You can literally see it in their eyes.
And I also - finally - know the opposite feeling. That of admiration and appreciation.
Please show this to your brother.