We need to go back to a 90% or higher tax rate on income over some threshold, and fix the loopholes that let wealthy people have income that doesn’t count as income. Especially the “take a loan and pay that back and all the activity there doesn’t count as income for tax purposes” bullshit.
And tax corporate profits more, and make a corporate tax system that rewards real R&D (while auditing to prevent fake tax shelter R&D), rewards higher employee salaries and better benefits (instead of taxing those), and rewards infrastructure investments like new factories but also investments in efficiency, water use reduction, etc.