But what gives you the edge isn’t having the best code. It’s building quickly, finding product-market fit, and masterfully marketing a good-enough product.
In fact, I'd say a good 50% of startups (or more) now fail because they put all their focus on the tech and have no idea how to get normal people to use their product. You can see it all the time with 'alternatives' to sites like Facebook/Twitter/Reddit/YouTube/whatever. Oh joy, you're using a blockchain with machine learning technology written with the latest JavaScript framework. And? Who cares, no one's using your damn site because it's got nothing worthwhile on it. Focus on building a community, not an engineering team.
So yeah, an average programmer can create a great startup. They just need to focus on getting people to use their service or product rather than coding a fancy one.