"falsehoods developers believe about screens" ?
Building responsive client UI is hard. In my experience here, the falsehoods HNers believe about clients is that it's somehow not hard. Or just a silver bullet away from being easy (like replacing JS with $faveLang). Or that resources are infinite such that every defect is explained by incompetence (except for, presumably, that HNer who is intimately familiar with resource finitude in their own life).
For something so universal ... there should be a very clear and unambiguous function call and at least a rational way to move through the fragmentation molasses.
For example, "What every programmer should know about memory" covers memory but what about (as you say) screens.