They sell that. They also sell tea and milkshakes, but you can go into any Starbucks and get a cup of drip coffee, or an espresso, or cold brew, or a mocha. But people like the sweet drinks and Starbucks is happy to oblige.
They roast their beans too dark because they care more about consistency than subtlety or complexity, their anti-union pushes are bad for workers, they displaced a load of small coffee shops (I have seen significant rebound, but that might just be my region), there’s this new “supercommuter” nonsense.
Pointing at a Frappuccino and saying “they don’t even sell coffee!” has no negative impact on their brand or business, it’s a transparently pointless claim to the general public, and it distracts from the very real problems Starbucks has.