I see evidence of Trump being able to acknowledge mistakes internally and making adjustments.
You're about the only one.
And yes, he makes adjustments... so he can make all new mistakes.
But lets say you're right, and that he is capable of learning from past errors... Being president means you're going to be presented with a wide range of unique problems. Some would rather have a president who doesn't make mistakes to begin with, rather than someone who will make a mistake, adjust, and try again.
He's not in the poorhouse after all, despite dozens of allegedly bad business decisions.
As has been explained multiple times in this thread... Trump had the benefit of $
millions due to family connections (inheritance, loans, credit). You can be a horrible businessman and still avoid the poorhouse if you stat with enough money to cover your mistakes.
It should also be pointed out that its possible for someone to give the
image of success without actually
being successful. Remember, Bernie Maddoff looked really rich even though his wealth was all a scam. Trump could very well be penniless (or at least with debt exceeding his assets), but still look rich if (for example) he's arranged with his financiers to delay collecting on debt.
Lastly, keep in mind that at least some of his money comes from things like his appearance on The Apprentice. Trump has built his reputation on being a successful
businessman. Being a TV star isn't what people are imaging when they think "Trump is a smart businessman".
I thought he looked quite good standing next to the Mexican President. You could imagine him looking and behaving quite normal in meetings with other leaders (if you squint your eyes).
Except of course after the meeting he lied about what was discussed, with Trump claiming the Wall wasn't discussed, and the mexican president saying it was.
Simply "looking good" standing next to another world leader might be a good resume for a cardboard cutout, but not for a world leader.