He didn't get brexit done, it was already in motion for the beginning of proceedings to start, he just happened to be in the seat at the time. He's done absolutely nothing to move brexit forwards, he said he was going to work flat out on it and then went on a two week holiday. I'm afraid you seem to live in an echo chamber of Tory spin. Judging him against Theresa May? That's a high bar.
Getting fired from every job you've ever done does have something to do with whether you'll be a great leader. As does a history of gaffs and chaos that's followed him, as do the racism and the homophobia, they all show that he doesn't have a handle on himself or his work. It paints him in a terrible light.
So to does his record, as mayor and furthermore as PM where he suffered the most defeats of any leader in our history in his first few months.
He has lacked a credible plan or response for anything and you see that as evidence for the greatest leader since Margaret Thatcher? Through the looking glass indeed, the post truth reality.
I will agree he doesn't have to do much to be better than Thatcher, she was a dick. Major was a great PM and is the main reason for the good Friday agreement.