I think at this point luck gets far more of a focus than it deserves. It's become a thought-terminating cliche around the entire idea of why people succeed or fail.
Almost no one disputes that luck is a component of people making their fortunes, its caked into the word. (Fortuna, the goddess of luck, gives the word its first definition, the second definition as a large amount of money came later).
There's no 'most importantly' about immense success. No one is an Olympic medalist by accident. No one found their way to the moon by accident. And while luck was involved, no one became an oil tycoon by or started an ISP or laid underseas cables by tripping into it.