I think the reason Starbucks stays afloat is not their coffee, but their 900 calorie "coffee drinks", which they market such that people can pretend to be coffee snobs while drinking what are essentially milkshakes.
I don’t think very many of their urban or suburban customers in the US have this hang up - they sell out of Target and hospitals amongst other things.
There are enough 3rd wave coffee shops around of varying levels of snobbery that people are aware of what’s available.
Starbucks gives familiarity and consistency.
Well by definition it's a lighter roast so maybe that's why?
My parents are smokers. There were few times cigarette ash accidentally got into my mouth. I swear Starbucks coffee and cigarette ash taste the same. I've had it from a couple of stores and both tasted the same. I can't help but think someone else in the comments is right in that people don't go for the coffee but for the stuff that hides the coffee.
McD's coffee is also bad (acidic, weak flavor).
I'll take the consistency of McD coffee over almost any other establishment.
And given their traffic volume, it's almost always guaranteed to be fresh, at a fraction of the cost of coffee-centric cafes.
