The short answer is that the rich get richer and the poor get poorer because the poor work for them and buy their crappy stuff because "Always Low Prices".
Costs are externalized and politicians are corrupted by special favors based on tax codes (see Trump's returns). The destroyers get a tax deduction for brainwashing people while stealing our time and attention (advertising).
Now that Democrats have the White House, there's little chance it will change because "sales taxes are regressive".
UBI based on sales taxes could eliminate so much corruption, so much paperwork, and so much paranoia by making the paying of taxes into an anonymous act and paying people a share of the Empire's extraction of resources from our places and people.
The problem is not that the billionaires are billionaires per se, but that the resources were wasted just to make them into billionaires, and none were invested into making actual leaders of an informed democracy.
The Invisible Hand Job is no way to run a country.
Now the short-brained will dump money into windmills and install a carbon tax that will be avoided and deferred without any effect on consumptionism. The billionaires will just come up with a way to suck the life out of the planet with solar power and deduct it from their income taxes on money that should never have left the ground.