McDonalds and fast food chains were always famous for being spotlessly clean, the best in the industry.
I worked at KFC as a teenager and it was very clean as well. If I was on an opening crew in a Saturday or Sunday morning, we spent an hour cleaning and disinfecting everything - counters, floors, grills, tables, etc. before we opened the store. The milkshake machines were washed/sanitized daily and the soft drink dispensers were thoroughly cleaned three times a week.
Not sure what it’s like these days.