https://www.aljazeera.com/features/2022/12/27/why-do-the-rich-get-richer-even-during-global
QuoteInequality is a political choice
After World War II, countries started following progressive taxation policies and took steps to address monopoly power, Ahmed said. And while many nations reversed that approach during the pandemic, a few bucked the trend. Costa Rica increased its highest tax rate by 10 percent and New Zealand by 6 percent in order to redistribute wealth.
"There are examples of countries doing the right thing. And it reminds us that inequality is not inevitable. It's a policy and a political choice," Ahmed said.
Aside from the obvious (the wealthy have access to the levers of power), I think one of the root causes is that most wealthy nations are gerontocracies too. So they have lots of policies that favor people with savings and assets.