"Wealth inequality" in the sense that there are several billion people and the net worth of each and every one of them is not exactly the same? That can't be it.
"Wealth inequality is increasing over time" seems like it could be a bad thing, but if that's the problem then what's the cause? Let's consider how that happens:
When you buy something for $100, part of that money goes to labor (the employees who made or distributed it etc.) and part goes to capital (the investors who own the company). Employees generally spend all of their income, so that's not an issue. As it turns out, so do most investors, by population count, because most businesses are small businesses. The owner of the local salon might be getting a dividend from the place but she's using that to buy groceries.
Then there's Larry Ellison. Screw that guy, am I right? Somehow that asshole has more money than it would take to buy the entirety of Boeing with enough left over to buy General Motors and Halliburton put together. And he's not spending it fast enough to make the number go down instead of up.
But wait, how did that happen? He definitely didn't end up with $200B by investing $100 in the Dow and letting it compound for 50 years.
His company did, however, get billions of dollars in government contracts and in general makes its money by selling copyright licenses to its 50 year old database software. In fact, if you look at the list of companies minting all of these billionaires, they're almost all tech companies, relying on a government-granted copyright monopoly that originally expired after 14 years.
And if you look at the ones that aren't tech, they're drug companies (another government-granted monopoly and an industry that has thoroughly captured the regulators) and finance companies (possibly the only industry with more regulatory capture than medicine).
From this we can notice a trend. You get billionaires when the laws impair competition in their industry and the industry consolidates into megacorps. So that's the cause. That's what you need to prevent.