That's also a reasonable suggestion. It wouldn't stop them from becoming billionaires. The GP suggested "every billionaire is a policy failure". What's the policy success that prevents this failure?

"No one is allowed to start a company by themselves"?

"No one is allowed to join a startup unless they get more than X% equity"?

"Startup founders must give more than X% equity to their first N employees and/or investors"?

"Bootstrapped startups are not allowed"?

"Once a startup becomes more successful than X, the founder must sell"?