I am also facing the same issue and report to Nothing and got my Ear(2) exchange to a new one, but the batter life was same about 2 hours. When I looked at the disclaimer part of Ear(2) there was one shocking parameter typed for ANC OFF 6 hours playback.
“BATTERY LIFE: THE EARBUDS AND CHARGING CASE ARE FULLY CHARGED WITH ACTIVE NOISE CANCELLATION TURNED OFF, 50% VOLUME, AND WITH AAC FORMAT AND THE REST OF THE FEATURES AT DEFAULT SETTINGS.”
I can assume, that playback time for both ANC ON and OFF can be achieved only by 50% volume, use AAC codec, NO EQ. Using LHDC codec, volume more than 50%, and enabling EQ or other function will impact battery life.