Think critically about your own mentality and what factors could contribute to a subjective decision: How much and how well do you know the other people involved with the decision? What past experiences could lead you to a biased view of the different options available to you? What assumptions have you made?
Preserving optionality means avoiding limiting choices or dependencies. It means staying open to opportunities and always having a backup plan.
The more options we have, the better suited we are to deal with unpredictability and uncertainty.
Knowing these and other biases is not enough. We need a framework for making decisions.