I don't live in Poland but I live in another country that does this and while I understand how some people might find it inconvenient, if you grow up with it and it's the norm, you just learn to plan around it. I also think worker's rights are pretty dope, so I might look more favourable on this than others. Edit: I forgot to mention this but think it's worth adding in retrospect due to relevancy - our public transport schedules change accordingly as well! Busy lines aren't affected as much, but everywhere else the intervals in arrival times are often greater on Sundays, especially in local public transport.
Not all stores are closed. Sometimes stores on sundays are open but noy for long but there is a special store thats cald żabka that is always open Like i mean 23/7.
It's Poland. Let the Polish decide. Everyone has an opinion on every single thing America does, but we don't share that same sentiment for other countries. Let Poland decide and let's not care about it.
This is a pretty general idea. Many other places around the world also do this. It's okay to have an opinion on it and discuss whether you would like it or don't like it where you live.
It's not a tradition it's a new law, seemingly a controversial one. Personally I prefer how the UK does it where big stores aren't allowed to stay open late on Sundays