Chiming in to say comparing thermostat settings between houses is comparing apples to oranges. Your AC is only "on" or "off," changing the thermostat setting only changes how much time it's on vs how much time it's off.
On a 100° day, the HVAC in a well-insulated house with double paned windows and solid weatherization is going to be able to maintain 77° with little effort, where a poorly insulated, leaky house may struggle to even reach 77° with the HVAC running continuously. These two houses may have their thermostats set the same but their internal temperatures and energy usage will be different, maybe even radically different