but liberal regulation is to try to maintain capitalist markets against their own failures.

wow you discovered why governments exist! Good job, do you want a gold star sticker? If the markets and economies didn't fail, you wouldn't need government, ever, for anything. The entire point of the government is to fix problems like this.

A homeless guy can’t just immediately become a billionaire by saying that there should be a competitor of genetic testing with 23andMe.

no, but if he's a good public speaker, he might be able to get large investment rounds for a competitor to them, and then if the engineers and experts at that company, do a good job, he technically could become a billionaire, though that's unlikely from just one success.