Earlier quoted context omitted.
This isn't true, this year I have been on a train from Marseille to Berlin and German police checked everyone on the train for passports at the border specifically to check residence validity - and removed one passenger with a residence permit as he attempted to reenter Germany (he was informed he was not initially permitted to leave)
Those are random spot checks, there's no border between France and Germany where everyone's passport will be checked.
"Those are random spot checks"
So there are random spot checks where people will check passports. So "nobody will check passports" is false.