Bias is a heuristic that works good enough almost all the time.

You can be traditional and conservative without much thinking. Just do what worked for your grand parents. It's learnable and a winning strategy almost all the time.

Progressives need to skip the shortcuts though. If you try out new things, you are wrong almost all the time on an individual level and some things are wrong on a longer time scale and more catastrophically than others. Be progressive with the mushrooms you eat and you might kill yourself. Be progressive with how to manage the world and you might end up with total annihilation.