Yes it’s hard to generalize in IoT because applications can have such varying needs and requirements. Some sensors aren’t energy intensive at all and can last years on battery, others need to be hooked up to a power source (whether that’s solar, the grid, etc.).
However, my overall point is still correct, that improved battery technology has opened the door for a multitude of IoT applications that simply weren’t feasible before.
Thanks for reading and for the thoughtful response!