The problem is that 30 hours slowly becomes far less over time with software bloat and battery degradation. What I hated when I had a watch with a tiny batter like this is that if I wanted both sleep tracking AND the ability to track my morning workout, I absolutely had to remember to charge before bed. If I forgot, I'd wake up with a dead or almost dead watch and have to delay my workout.

I went though a number of android wear smart watches ~10 years ago and had the same problem with all of them. I absolutely loved my Garmin 945M. I had it for years with hardly any battery degradation and it typically gave me 70-80% of the advertised battery life for many years until it was accidentally physically destroyed (caught the watch on a heavy backpack I was taking off, which ripped off the watch pin anchor from the case).

The Fenix 6 I have now is not nearly so good. It advertises 2 weeks of battery and I'm at 53% after only 4 days or so. I blame this partially on their crappy iOS support where you cannot filter apps out, so every #$%#$%^ slack message I get buzzes my watch. I had a Pixel phone when I had the 945, where you can filter out garbage notifications. This is really Garmin's fault, since apparently Coros and Pebble can filter notifications on iOS. I'll switch to one of those when this Garmin dies unless they fix their iOS support.