Are you talking about their black coffee? Or their other sorts of drinks that are often less than 50% actual coffee? Because if anything, the usual complaint about literal coffee at Starbucks from people who like coffee is it tastes too much like coffee, in the sense of being over-roasted and uninteresting. Even their blonde roast is still at best a medium roast at any other modern roaster.

The thing that surprised me about burnt coffee beans is that people assume that the heavier the taste the more caffeine is there and that’s not true of over-roasting. It’s less available caffeine, not more. So it tastes terrible for no practical reason.

Today’s Starbucks is well removed from its origins. Starbucks was never great coffee, but I’ve heard it started out pretty decent.

Much like how McDonalds, KFC, etc started by making decent food so did Starbucks. Add 40+ years of optimizing for the bottom line and the average person’s pallet and you get a very different product.

Anecdotally I believe McDonald’s actually does very well on blind taste tests.

I am a bitter taster. It took me years of having chocolate in my coffee to work up to a latte. And even then I tended to adulterate it with hazelnut.

Cold brew is better, but not as much as afficionadoes sold me on. I can still taste the bitters.

This. And I'll also add that until I was required to try each variation of a certain coffee for a job prior bring it to stores, I was convinced there was no such thing as coffee that's not bitter. All coffee I'd had before tasted like chewing on aspirin[1].

For the job, there were five "espresso style" variants[2]. Although the "black no sugar" was too intense or me, none of them were bitter. I could make them bitter if I left one open too long or by heating one and letting it cool. There are only three variants now, and I miss the the discontinued "black lightly sweet" and "mochachino".

I've since experimented with making cold brew, servedhot or cold, with a little potassium bicarbonate. I've also tried some ready-made cold brews and lighter roasts. Darker roasts taste more burnt to me. Robusto is unsuitable. Arabica is better, especially if it has a good proportion of Kona in it. If it doesn't specifiy how much Kona, assume it's not enough to make a difference. I haven't tried pure Kona, even while in Hawai'i, because price.

[1] This was not planned. I was mistakenly given regular tablets instead of children's chewable…more than once, by different people. Not a recommended experience.

[2] I'm told Italy made them stop calling it that, because of some legal definition of what constitutes espresso.