If we accept the (increasingly uncertain) assumption that democracy is sustainable, and that taxation policies reflect the wishes of the majority, then we would expect (to a first approximation) that the wealth distribution in a country would match the average or majority wishes of the citizens in that country.
As for what the "desired" wealth distribution is, a naive view would be that everyone believes that we are all inherently of equal worth, and therefore we should all have roughly the same amount of total assets over the course of our lives, but a lot of people instead accept the premise that if there were no reward for working hard, people would freeload.
Fortunately some research has been done on what the desired amount of inequality is, and here is an article[0] which compares that desired distribution to the actual distribution, and also to the distribution that people think exists in America. The results are quite illuminating.
One way to bring the actual distribution in line with the desired distribution (other than improving democracy/representation and education) would be with an explicit annual wealth tax. For simplicity it could be designed to only apply to people with more than $5 million in net assets, and it might have to be agreed in coordination with other advanced countries (like the recent global minimum corporate tax rate agreement). The revenue could be redistributed into public services like free healthcare and college.
[0] https://www.theatlantic.com/business/archive/2012/08/america...