Education takes time and needs to be done. It does not solve all problems before they arise.

That is true, but it's not intended to solve every conceivable problem, but to make them easier to navigate when they do appear, and can also be backed up by support and guidance. This is why such education should be given early in the lives of kids.

If an activity involves several people, is dangerous for one but not the other and is consented to by the party who is consenting, is caution also the responsibility of the other?

Yes, most def. People should consider the well-being of those who may be taking a bigger risk than they are despite the presence of consent.