When I lived in Poland everything was still open on Sunday and when I moved to Spain everything was suddenly closed and I had 0 issues adapting. I’m sure it’s an issue when traveling but once you make that mental switch it’s super easy to plan around it. I remember having discussion on reddit later and people form Poland coming up with the craziest reason why they need the stores to be open on Sunday (like “I’m disabled so I drop food all the time and what I’m supposed to do when I drop my last food on the floor and it’s Sunday?”… IDK, buy more food on Saturday?)