So, capitalism is itself defined more than one way depending on who's talking, and I only have a problem with some versions of it:

In the sense that certain people get to just own stuff, while others have to work, I'd say capping wealth at like 7 digits would be a simple solution. You can save up a few million across a high-earning but normal career, but nobody makes it to 8 unless they're a bigshot. Over time random social mobility should hopefully smooth out the remainder of class distinctions. If not, maybe 6 digits, although some dentists are going to be pissed.

In the sense that we organise our economy around profit motive and competition, I don't have an issue with it because it seems to work well. If you need to buy something, there's always somebody selling it and vice-verse. If you look at history, or at the crazy supply chains that exist to facilitate that, it's quite an achievement.

In the sense that people privately own the means of production, there's a bit of a trick deciding what the means of production even are. A foundry definitely counts, and a toothbrush definitely doesn't, but what about a van, which you could use personally or to transport people? You could licence them separately depending on use, but then you couldn't work as a "rideshare" even if there was a major shortage of taxis, which is dumb red tape. It's far more productive to talk about things in terms of their market value rather than getting any more granular, which is why the law usually does that.