I’ve flown Singapore Airlines before (not first class) and they are excellent, their seats are comfortable, the food is good, the flight attendants are gorgeous and friendly. All of these characteristics are way better than on U.S. airlines.
Watch the video below to see the comfort and attention first class brings with Singapore airlines.
By the way, do this thought experiment. Suppose someone were to offer to let you watch movies for a few hours in a really really comfortable seat plus really decent food.
Now as a choice, you can watch the same movies, bring your own food and get paid $1500.
From game theory, this is the exact same choice as taking a coach seat versus first class. Why would anyone but the most wasteful people fly first class?