if we're talking about a device that only needs centimeters worth of range and spends most of its time in deep sleep, those 50mA could last quite a while.
Microcrystal can make these things to run at <50nA. https://www.microcrystal.com/en/products/real-time-clock-rtc...
All the BLE manufacturers are 1uA plus. It's infuriating.