Popularity of Starbucks

I considered why Starbucks is so popular among all generations.
The first reason is cleanliness inside the entity.
In some restaurants, there is dust on lamps dangling from the sealing, but I didn’t see any dust on it inside the coffee shop.
Secondly, the variety of menus attract a lot of people.
I don’t really like coffee so I sometimes order tea instead of coffee.
Also, new menus are launched regularly, so customers enjoy different seasonable tastes.
The final reason is location.
When I think about the locations of its branches, they are at very convenience places to visit.
Those are the reasons why Starbucks are popular all the time.
I want to make an interview to the staff someday.