The defeated idea may have shaped the winning one more than the winner admits.

Winners absorb their opposition. The argument that lost usually forced changes, closed off options, and shaped the final form of what prevailed, and then the account gets written as though the successful idea arrived complete and unopposed. The defeated position is present in the result, mostly as the shape of what had to be answered.

When something wins an argument in your own field, look at what it had to concede along the way. And when your position loses, notice that it may still have altered the outcome. Influence and victory are not the same thing and only one of them gets recorded.