Spanish comedian Ignatius Farray. Dude was born into a poor family and was a loser with plenty of mental health issues, didn’t gain notoriety until traditional entertainment industries in Spain lost ground to new online spaces, after a decade and a half of mediocre results.
You still have a point: it’s far easier to become famous and successful when the cards are stacked in your favor, but that argument sucks because you only need one counter-example, which you definitely are going to find in a world with billions of people.