Shops closing on Sundays in Germany is no workers rights issue. No one is asking workers to work 7 days a week.

Germany as plenty of students, for example, who'd love to have a job on the weekend because they have the freedom to choose a bit better when they work and when not.

The reason Sunday to this day is still a day when almost all shops have to close is mostly religious. There are restaurants and some other shops that are allowed to stay open and most of them choose either a different rest day or make sure that they have someone on any of those days. One workday on a Sunday is plenty to fill out a typical untaxed low payment job that are very useful to students and others looking to just get a bit of an income.

Actual workers rights aren't telling people that they can never work on Sundays, they're guaranteeing people that they will never need to work too much.