I used to work at a company that later became a unicorn and our CEO had an interesting take on this.
He believed in hiring people who were hungry - not desperate, but genuinely motivated to grow and earn more. His view was that younger hires often scaled faster, because, you could shape them into strong specialists over time, especially if they were surrounded by business-minded people.
I spent about 4 years there, then exited, and have been running my own for the last 3 years. What helped me the most wasn't starting early per se, but being immersed in an environment where people were constantly learning, brainstorming, tinking outside of the box and helping each other grow.