This is a deep topic worthy of an essay, the kind of essay pg might write! The concise reply is, when you catch yourself in dichotomous thinking, you should assume you have misunderstood or oversimplified.

Sometimes you have to go with your misunderstanding or oversimplification to make a decision or to make progress, but keep in mind you are doing so based on beliefs which are unlikely to correspond to reality.

It's striking that so many mental health difficulties are characterized by dichotomous thinking. [1]

Rationality itself can be profitably critiqued at the meta-level.[2] So, don't be an asshole, unless you need to be. Do you see the world as consisting of assholes and non-assholes? How does that feel? What are the advantages of that view? What are the disadvantages? Is considering that question worth your time?

[1] https://www.psychologytoday.com/us/blog/she-comes-long-way-b...

[2] https://metarationality.com/introduction

EDIT: Fixed link, spacing