Yup currently the end game farming is not very end game and once you got the items you want there is no where to use them really especially on eternal.
Pvp would be the answer as this most end game activty I can think of utilising all the gear and knowledge you can get especially again other skilled pvpers, however this part does not exist on eternal and is quite limited on seasonal although there is small active scene there. Ofc pvp is not everyone cup of tea but at least it meets end game content expectations even in such unbalanced environment as D4 is.
Pve wise nope you farming duriel for nothing in terms of next step once you get your uber gear and duriel is hardly end game.