I wasn't assuming you were talking about "eradicating racism from planet earth" - that's a bit of a strawman. "Stopping blatant racism" is moving the goalposts, because "blatant" wasn't part of the original context.

As you say, you can stop someone overtly declaring their racism, but that doesn't mean they won't still covertly (or even unconsciously) continue with racist behaviors. Which is why it isn't so "clear", because even a simple situation with coworkers, you can be facing an uphill battle.

Anyway, I would wager we both broadly agree and this is now just a semantic argument.