Having read this site and overcomingbias.com for a while, my conclusion is that stong opinions are not at all about maximizing the accuracy of your mental model of the world. Rather they are about influencing people around you. In the social world, it is more valuable to influence other agents to work in ways you want them to than it is to be accurate in your understanding of the world! Or at least the default accuracy you get is sufficient whereas the default influence you would have without strong opinions is way below optimum.

I think people trivialize the thing they call "signalling" when they call it signalling, as if it was some decoration evolution has added to otherwise useful actions. If you influence 20 people an average of 2% each, you have increased your agency 40% over just what you could do alone. Even more than 40% if you consider much of what you are doing comes from the influence of others on you. Signalling, if that is the best word for it, is WAY more important in terms of getting things done than is understanding the world. I imagine this is true because "most" of the world is already understood at any one time, meaning there is plenty to gain using what is already understood with a bunch of influenced people, more to gain than by not influencing people and using resources to try to figure out something the rest of your peers don't already know, or have wrong.