it doesn't mean it happens because they worked hard or that everyone who works hard will be successful. There are other factors
But in most scenarios, not working hard will definitely rule you out entirely.
Every time an 'ideal career' thread comes up on Mn, multiple people say that they would love to be a writer, specifically a novelist. Yet most of those people have never finished a single novel.
There is absolutely nothing stopping anyone writing. It requires no training or expensive equipment, and you can write on your phone at a bus stop or on your lunchbreak, or by spending less time watching TV or on SM. You could do it, slowly, in 15 minutes a day. I wrote my first novel on maternity leave with PND while doing an international move with a newborn. It never sold. So I wrote another one, while working FT with a toddler.
Most UK writers do not earn enough to live on by their writing alone, and of course there are trends and fashions you can be lucky or unlucky with, but if you don't actually put in the work to write, finish and revise to make something as good as it can be, you don't even get to the starting point.
The difference between me and the people who say 'Oh, I'd love to be a writer' isn't talent. Mostly it's because I put in the work and they didn't.