But in theory if you could pay for groceries with monero (you can't afaik), you could pay from the same wallet you conducted a hack from or purchased a darknet server to host leaked data with. The grocery store wouldn't know the originating wallet or any of its other activity.
Anyone who thinks grocery stores are going to allow monero payments is pretty naive, but Monero at least makes these flows possible.
For example, if Walmart decided to let people pick up orders with monero payments, you'd log in with your walmart account (linked with real name), place your order, pay to the generated wallet address with Monero, and then show ID on pickup. Walmart would have no way of knowing where the money came from.
I don't have any Monero or particularly like it (but mainly because I consider proof of work unsustainable and wasteful). But you have to admit the privacy implications are interesting, and the technology is impressive.