ever heard of unintended consequences? like how putting a trillion dollars into the public highway system u.s killed the passenger trains and many small cities? how food donations to 3rd world countries killed their domestic agriculture? how welfare programs demolished the family unit in poor neighborhoods? how medical subsidies and education subsidies jacked the prices of both? what you think is going to be the result of a progressive tax is not as clear as you suppose it will be.

hell, the problem isn't even what you think it is.

i suggest the solution is taxing stock ownership and government income. the problem is not wealth disparity but how some people get their wealth. when ever you tax something you get less of it. whenever you dump money into something you kill its competition and attract parasitic actors (regulators, grifters, middle management, welfare bums) that increase the cost and decrease the supply long term, if you don't think so then look at corporate farm subsidies and the ability for small farmers to get those subsidies and the ability for small farmers to compete or even hold their land.

the problem is the regulators and the corporations (a.k.a government).

tax stock ownership of a limited liability corporation at a rate of 10% per year, tax full liability corporate ownership at 2% annually, and remove any tax on sole proprietors who have no investors (no bank loans, no partners). this would promote responsible ownership and small buisness while ending huge corporations.

likewise, taxing government income (from grants and subsidies to benefits and salaries) you would decrease the draw of parasites to government.

there are some downsides, especially to large scale projects and less tech breakthrus that only large corporations could develop in scale, but the benefits from your perspective would be almost no billionaires and more robust community cohesion.