My family ran a local sandwich shop for years. Here’s the problem.
If this is downtown, the local sandwich shop isn’t even there, in part because Starbucks helped price them out of being able to rent. Every supermarket now has a sandwich counter too, so local sandwich shops don’t do well in shopping centers either. Fast food has slightly improved their quality over the years so that’s more competitors at the low end. And Subway, period.
You’re paying for the convenience at Starbucks and in some cases convenience is valuable. If you don’t care about time and can go out of your way to a local sandwich shop, you get better food for less.