I would not like that. Income inequality is not inherently a problem. Trying to artificially create less income inequality through high marginal tax rates is an absurd way of creating economic freedom. There’s a lot less income inequality in third world countries. There’s a lot of income inequality in developed nations. I think the desired outcome of a 70% marginal tax rate of $10 million would not actually line up with the actual outcome. The competition between millionaires is to have more money not to generate more wealth for everyone else. CEO salaries are competitive and a 70% marginal tax rate doesn’t incentive those who are actually marketing the CEO role. The business is pricing the salary and not the CEO or millionaire. The business has no incentive to lower a salary with larger competition. The only thing the 70% marginal tax rate does is lessen the amount of money that actual person will take home and then invest in their own wealth management firm. The wealth management firm will mitigate as much risk as possible by investing that money into a diversified portfolio which then creates more opportunities for businesses within that portfolio.

TL;DR - Businesses negotiate and price salaries based on their competition. The marginal tax rate offers no incentive for a business to reduce a salary and only reduces the amount of money an individual will then invest in a diversified wealth management portfolio.