Apple Watch Ultra has juice for about 10-13 hours of active GPS activity tracking time. Non-Ultra Apple Watch does less. My Garmin Epix2 can do about 24 hours with full battery, Fenix series does a bit more.
My ex would leave on GPS tracking when we'd go out so he could re-draw his route later, and his Apple Watch would almost always be dead before dinner. Just my N+1 anecdata, and he was using an older (Series 3?) model.
Although the two are not directly comparable of course, when is more of a fitness watch, the other is a general smart watch with fitness functionality.