Lots of businesses have websites that can be found on other search engines. Those websites often include their opening hours.
Sure, I can go to 15 individual websites, select the specific branch I want (if I got another map service to spit out names of bakeries) and hunt for their opening hours in 15 different styles of menus.
Google is just really good if it can sell you something. And sometimes, I need something to be sold to me.