Software development topics I've changed my mind on

As always on here, a lot of people appear to act as if there are universal truths about our craft.

I would posit that the exact enviroment you are in changes massively what is correct, what is a good rule of thumb and what is a bad practice.

What applies to a game developer does not apply to a web developer. What applies to a product developer does not apply to a library developer. What applies in a startup does not apply in a legacy org.

I'm sure there are some universal truths, but usually they are principles and not prescriptions.

E.g. Code should probably lean toward readability, but you quickly come up against time constraints, language constraints, performance constraints, interpersonal conflict, etc.

Edit: To that end, I would ask that when discussing what we find to be useful or not useful, that we caveat with the enviroments that we have found this to be true.