It sounds like OP had an expectation of (good) Int'l level F service because s/he was sitting in F on a 3 cabin plane. But UA does not work like that on non-PS 3 cabin aircraft, IME. On mainline UA domestic flights in F, you get domestic F mainline service whether it is a 3 cabin plane or not. Service from great to meh, so-so to lousy food, mediocre wines.

The seats on the 777's are due to be replaced "any day now" as part of the premium cabin upgrades. UA is slowly working its way through the 777 fleet at long last. Give it another year +/- before most 777's have the new seats. Until then, the best you can do is hope for a plane with a new cabin or an old one with stuff that still works.