The idea that packing is more stressful than checking your documents ignores a fundamental asymmetry between the two tasks.
A missing or invalid document can cancel the entire trip, like redoing an expired ID at the last minute, making everything else useless.
The stress of documents is a matter of absolute prerequisite for the trip itself, while luggage concerns the comfort of the experience, not its existence.
Achieving maximum performance in trip preparation means ensuring it will happen, and that depends entirely on papers.
A flight without a valid passport will get you nowhere, no matter how neatly your socks are folded.