This advice falls flat in case of validations. If a function is given some input and is supposed to work with it, how can it avoid if/else and how can we move this logic one level up to the caller to ask the caller to verify every parameter before calling the function?

And if we keep pushing (thus pending the decision making) up, wouldn't the top most function become a lot more complicated having a lot more logic pushed up from far down below?

That's bad and impractical advice but now will pollute many pull requests with needless arguments.