True. But skill also. Luck let's you roll a 6 if you need one. Skill makes sure you get to the roll the die 10 times.
A "lucky break" is more likely to come along if you keep at it for a decade than if you give up after the first non-successful year.
I think skill comes in two forms: The skill of making something that people want to use, but also the skill of recognizing and making the most out of "lucky breaks".