As well as tax inheritance at 25% or progressively.
Wealth lasts for generations, and you don't pay inheritance taxes on family connections or a top tier education. New taxes that make the accumulation of wealth more equal, i.e. progressive income taxes or capital gains as income taxes, will not erode the existing wealth disparity within our lifetimes. Just look at how the policies up until the 80s resulted in white Americans owning all the property, which subsequently appreciated due to monetary policy.
If wealth inequality is a problem, which I believe it is, you should tax wealth because it directly reduces the gap in absolute terms.
Inequality is deeper, inequality should be targeted with things like free access to university and technical schools, policies that target housing prices to keep those lower or progressively tax homes with property taxes to reduce expensive homes, tax empty homes, fix health care so a base level is included as part of taxes for every citizen, expand childcare/school to age 3 months, pass paid vacation on a federal level of 4 weeks, bump minimum wage, pass an inheritance tax of 50% on anything more than 1 million, etc.
Thinking a wealth tax fixes anything is crazy. Just look at all the case studies out of Europe. All it does is create more loopholes, reduce business investment, and cause capital to flee.
Also, inequality in the right ratio is good. Now we just need to figure out where that ratio should be. I think the USA is obscene right now, but mostly because we have enough money to build a real working society and instead we've built a cage to fight to the death within.
Europe has some really bad policies around not letting companies die that need to die. It is really hurting them. I am hopeful that they can remap labor policies to allow for more flexibility to compete with the USA while keeping a real social safety net through payroll taxes and government "insurance".
Europe also needs better bankruptcy laws to allow for people to start over. The USA has the best bankruptcy laws in the world right now IMO. Europeans can't afford to take risk or access capital because of some of these policies.
I am living in Spain btw, about to move to Portugal. I am leaving because of the Wealth tax here is so poorly thought out it would take 60%+ of my income and I couldn't live on what remains. Especially since I am starting a new business.
Note - We could also stop the step up clause for inheritance which makes me angry. So that when someone dies and the assets pass to someone else they pay capital gains instead of zeroing it. This is such a loophole for rich people.