Switzerland - shops really closed on Sundays?

Most shops will be closed on Sunday in Switzerland. You can go to Lucerne, Interlaken or any city, search for shops, groceries, etc and Google maps will show today’s hours and with a drop-down arrow show you all of the week’s hours. I did a quick search and more than half but not all indicated that they are closed on Sunday.

It's been like that for a very long time so don’t leave any shopping until Sunday. I once had to plan a birthday dinner and cake for a 1 year old in a small city in Switzerland on a Sunday, the day after our late arrival. I brought a candle and some ingredients with me. The rest we had to buy at the grocery store that was open in the train station on Sunday.

From Luzern station site
https://www.sbb.ch/en/travel-information/stations/find-station/lucerne-station/shopping.html?tags=1&page=1&pageOpen=1

Everything for your daily needs. 365 days a year. From early till late.

Generally, yes, non-tourist businesses are closed. But if you know about it, you work with it and it's fine.

Stores at the big train stations are all open. Restaurants are open. Trinket shops in the tourist centers are open. Five trips to Switzerland and it has never been an issue. Christmas in Switzerland did take some planning, but a regular Sunday is very doable if you are aware

Absolutely! Sundays are for spending time with friends and family, outdoors if possible. As stated above there are some convenience stores open, one pharmacy in town will be open, larger train station shops and some tourist shops open, but if you are hoping to go to the big department stores, etc. they will be closed.

I've also found that many shops close early on Saturdays, around 4pm. Enjoy your visit in this beautiful country!