It's one law that every single country has on the books and no one ever enforces - observe how it has no provision for anything that you actually own, if you go out of EU with your MacBook Pro and come back you should technically be declaring it at customs as an item over the allowance value. You should be declaring your phone and your watch if it's an expensive one too. Literally no one does this, and if you do try declaring those items you will be just waived through for wasting the guard's time.
You have very strong opinions for someone who really doesn't understand import/export at all.
Of course things you owned, left the country and are returning with are exempt.
Import Duties apply to items purchased while outside the country and that you are returning with.
If you were away long enough to establish residency, there are usually exemptions to items of personal property you are bring back with you.
The duty-free allowance is different for every country, but in Germany for example it is around 450€ per person (the exact number escapes me). Any goods you return with in excess of that amount is subject to duty.. Some items you return with are always subject to duties.
In Germany for example, they very much will check for this and enforce it.