I have an iWatch, gifted to me by one of my daughters. While I like all the features, I would never buy one. The battery life is crap.
I have an Apple Watch 6, my brother has a Galaxy 6 watch. My watch battery lasts about 28 hours while his barely makes 13 hours.
These devices do a lot of things, with very small batteries.
I bought the original “Samsung Gear” smartwatch back in 2014. It came out before most other “smartwatches” and “fitness trackers” that I am aware of, although I did have purchase the Polar CIC Heartwatch in the early 1980s. It recorded heart rate data for up to 12 hours and I had a serial interface to hook it up to a pre-windows based PC to make graphs, etc... I was a champion bicycle racer in my early years.
The Samsung Gear watch was actually useful and customizable for quite a long time, although the Polar Heartwatch with a chest strap was far more accurate. It was funny when years later people started showing off less capable devices. But it was designed to be used with Samsung phones to take advantage of all of its features. I used it with Samsung S3 and S4 phones, but I eventually had to switch to a newer phone after T-Mobile took over Sprint and they gave me a much more capable “5G” phone. But I still miss the Gear watch a bit.
I was a little disappointed to see that the original Apple Watch didn’t seem to have as many features as the Gear smartwatch and was not as customizable. I didn’t think it would take off, but one should never underestimate the determination of Apple customers to part with their hard-earned cash.