It helps to stop some rapes. For example, it would reduce the rapes where some young men are told by other men that women who wear someway or do certain things "want it", so they would stop to falsely assume that doing those things equals to consent. And yes, some men are that deluded to actually believe things like "when women say no they meant yes" because there are plenty of films and TV shows telling them just that. And because they are taught that what men say is inherently more trustworthy than what women say.

Not just that, but that women "doesn't know what they want". So there is plenty of false propaganda designed to justify rapist. So teaching about consent would also help to reduce the number of excuses for rapist. Once people have a clear idea of what informed consent means, they would be less "grey areas" and their excuses would be less believable making it easier to help rapist accountable.

Of course rapist don't care about consent. But they care about "plausible deniability" with other men who do care about consent. The clearer the meaning of informed consent is, the more difficult it would be to deceive people into thinking that there was consent when there wasn't.

We do know cases of men who kill rapist that have raped someone dear to them. Sometimes the rapist was known to them, but they didn't knew it was a rapist, they didn't identified the rapist as such. Why? Because rapist lie and we are not taught about how to identify them. We are taught just the opposite, to justify them. Educating about consent helps to identify people who doesn't care about consent. We can still be deceived, but it helps to make less excuses for them.