I posted an article a few months ago saying that premium economy is projected to be the new battleground for airlines. First is almost history and apparently business is also thought to be weak, although ironically some airlines have no trouble filling that part of the plane on the long haul routes.
Anyway I just did LAX-Paris roundtrip on Delta in comfort class/premium econ whatever you want to call it, and it saved my life! I've been saying for years I want the seat from business class but don't need any of the other stuff, and that's basically what PE is. You get actual legroom! Actual honest to gosh legroom! And a slightly nicer seat, but mainly the legroom! Can you see what I'm focusing on? It makes such a difference on such a long flight. The food isn't any better, and the "amenity kit" was an eyeshade, earplugs and earbuds, but the attendants are slightly more attentive and (once more) you get legroom! And dedicated overhead storage which is helpful.