Well most showrunners for shows started as storyboarders.
Rad Sechrist who made Kipo and the age of wonderbeasts was a storyboarder for dreamworks.
Same with the creator of Steven Universe, Spongebob, and others. All storyboarders. Essentially being 'proven' in the industry is a prerequisite for people with the money to fund your stuff.
​
Source:
Ultimately one has to be realistic about ones goals. If you want to do everything on your own a webseries is the most one can do when one is fully indie.