I wear a fitness tracker. If I'm gonna wear something on my wrist, it ought to do something that my phone doesn't, otherwise it's hard to justify the cost.
The same is true of a smartwatch - you get the some of the functionality of your phone without needing to have your phone on you.
No, it doesn't, that's the whole point I was trying to make. My fitness tracker tracks heart beats for example.
The Blaze is newer than the Surge; it's basically a Surge with a color screen and the face detachable from the band (which is much better for charging, as well as making replacing the band practical) but without independent GPS (which means if you want to do run tracking without carrying a phone, the Surge still has an advantage.)
The Charge 2, IIRC, replaced the Charge about the same time as the Blaze was introduced, it's basically the next tier down from the Surge/Blaze.
(Current Blaze and former Surge and before that Flex user.)
I have a (very modest) collection of watches that I enjoy wearing but I also like the data collection of a Fitbit.