The average person has $60k-ish a year. There is nobody out there with 60 trillion.
Regardless, the billionaire has to actually spend the money to get goods and services from the market. While his/her needs will dwarf an individual, they are still just a drop in the bucket compared to the middle class. This is why all of the largest companies/product markets/etc all cater to the middle class.
The only way billionaires can actually get leverage on how society is run is through direct monetary influence of politicians, but that’s going to happen whether the average income is $60k or $200k.
But anyway, whether it’s a billion times more or merely a million times more, the difference is still staggeringly huge.
If you have a dollar, how many more do you need to make a billion? About a billion.
If you have a million dollars, how many more do you need to make a billion? About a billion.
But not for all aspects of society. Pre-democracy, kings and royalties get to make these choices. But in western democracies, you at least have an unalienable vote which is independent of your economic output. This vote means that no matter how many billions get spent, this vote is up to your own decision.
He's definitely right that it is valuable to society that people who have such insights are given the opportunity to build their solutions. We all win from being in a society where more of our needs are met.
What's perhaps slightly more dubious is the idea that, by bringing that insight, the person who has it deserves to own a billion times more of a vote in how our society is run than the average person.
Because that's what wealth, what a dollar, is: it's a voting share in how society spends its time and resources. As the owner of a dollar, you get to decide whether people spend their time growing and picking and shipping some plants and making them into some bread and then putting together a sandwich for you, or if you'd rather they dig up some rocks, extract some silicon from them, imprint it with complicated patterns, and then construct it into a device you can put in your pocket that lets you see photographs of influencers.
The pg thesis here is that instigating an idea, creating something that doesn't exist, is not inherently exploitative. That is true.
But what is perhaps arguable is, that in delivering on that original founder's vision, one which attracts many of those votes for how society should spend its time from many people, and thus accumulates billions of dollars of revenue - that many people other than the original founder end up creating the organization and building the factory and working the machines and writing the software and actually serving the customers to make that solution real - a bunch of people other than the founder are involved, and... well, if you choose to structure the rewards of that organization so that all those billions of votes in the future of society accrue to the founder, while only thousands of them accrue to the people who do the work of making it happen... that it's possible to construe that distribution of rewards as maybe slightly exploitative?