This means that even as a passenger with a completely clean record, every action you take is viewed through the lens of being potentially suspicious. The worst case scenario is not being delayed - it's being falsely accused.

Less importantly but hugely more likely is that you travel is disrupted. Your bags are misplaced or stolen. You can't take your water bottle so now you have to buy another for 10x the price. Your passport was accidentally torn so you now have to explain that to a skeptical border police officer. You don't speak the foreign language well enough to explain yourself. Your flight is cancelled and you must now rush to the only hotel to book a room before they sell out - or risk waiting in order to convince the airline to book it for you.

I don't disagree with you that some relaxation can go a long way to making such an experience more pleasant, but it's still true that there's more to go wrong in one international journey than in a whole month of most people's day-to-day lives.