drethlin nailed it - If I counterfactually-had spent that time working on AGI, I wouldn't have solved Friendliness, and (unless someone else had solved FAI without me) my AGI would be just as Unfriendly in expectation as the competitors.

If FAI is solved first, however, it increases the probability that the first AGI will be Friendly. Depending on the nature of the solution (how much of it is something that can be published so others can use it with their AGIs?), this could happen through AGI development by people already convinced of the problem, or it could be 'added on' to existing AGi projects.