Why is it that wealthy or well off people always riff about how always being positive/realistic is a key to their success?

Yes, believing in yourself is helpful. But not as helpful as others believing in you. I’ve seen plenty of successful narcissists who believed in what they were doing while at the same time being completely full of shit.

If you can’t get others to believe in your projects, you aren’t going anywhere. And for every success story in hustle culture there are a thousand others who failed. And a large percentage of those failures were because one or two things failed to break their way at the right time.

Wealthy people want it to be about their work ethic or their intelligence. They want it to be about the actions they took.

Do people fail because they didn’t start? Yes.
Do people fail because they fuck up? Sure.

To get from nothing to well off takes luck. No amount of knowledge or hard work will substitute. If you don’t have relationships which foster that luck, you aren’t going anywhere.

That’s not an excuse to not take those chances, make that effort, or to not network. If this is what you want then go for it. But don’t delude yourself once you are there that it was your exceptionalism which made it all possible. Don’t be that person.