With my wear OS watch I love being able to passively track my steps and constantly gauge by blood oxygen level and heart rate and also I guess the increased GPS accuracy is nice even though I don't really go anywhere but I could turn that off if I want to. I also use it to do enhanced sleep tracking. So pretty much every sensor is always going on mine along with the Bluetooth to communicate with the phone. I also have the display always on and the display goes to a low power mode that's always on that turns everything into like one bit black and white. And I leave the display on the lowest brightness when I'm inside and I turn it up I guess to the max when I'm outside.
I get about 2 days of charge before it gets low enough that I gotta plug it in.
If I wanted a watch that was a just a watch I would just buy a watch and not a smartwatch and then disable all of the smart features.