I have no novel idea, if that's what you're asking. Taxation worked fairly well for a long time. Our current 40-year-old system has been constructed around lower tax rates and tax incentives given to business. So, while the former, steeper progressive tax code helped keep the scales somewhat balanced, reverting back to 70% nominal rates would need to be done gradually. I would have no problem taking 70% of Musk's wealth from him as taxation.
Entrepreneurs are a given, but an entrepreneur is an efficiency specialist, not necessarily filled with material ambition above that of a normal parent. The question is, do we need ambitious actors whose only goal is the accumulation of material wealth? I'm not sure we do. We might. Tough question. I ask myself, "Would anything be different if John D. Rockefeller hadn't been born?" In other words, were the infamous Robber Barons (for example) a necessary cog in our economic wheel? I don't know.
The balance between economic freedom and societal cohesion has always been a work in progress. I totally disagree with Bernie Sanders' billionaires shouldn't exist position. I also think allowing private citizens to accumulate wealth with potential geopolitical consequences is dangerous.
Here's a stark but true description of capitalism vs society.
If society were a family, capitalism looks at that family as unrelated individuals, whose only motivation is the self. Like I said in the other post, we are capitalists and humans. We are family, and we are related, and our motive of course is self-directed. It's not a new problem. We are necessarily moral beings whose survival requires amoral behavior. This would seem unremarkable if not for the fact that some of us, sometimes, engage in immoral behavior.
Okay, that was way too deep. My answer is taxation. Slowly take some of the money back. People like Rockefeller and Musk were/are addicted to power more than money (that's why they're dangerous.) After a certain point, we are not taking material wealth from such people - they have more money than they could possibly spend - we are preventing them from gaining the power to alter the political landscape on a global level. As power is their main ambition, and they have more money than the pope, high taxation will not disincentivize their behavior, as is often claimed.