Even if that's true, it still implies that everyone else mostly aren't idiots, because otherwise it wouldn't take luck to get rich, all it would take is outsmarting all these idiots everywhere.
Nope. Luck does not imply causality. Everyone can be an idiot (including you) and you can still be lucky. Or there can be a mixture of idiots and geniuses and you can still be lucky.
"Luck does not exist" is not required, because that's just a separate path to getting rich. You can win the lottery and it's pure luck. But if you're really smarter than everyone else then you should still be able to figure out how to get their money even if you only have the ordinary amount of luck.