After dabbling in Android Smartwatches in the early days, I had mostly given up on them and moved to using bands like Sony SWR10, SWR30 and then to Fitbits
Got the Galaxy Watch 5 Pro this time on my US trip (because cheaper + you can enable ECG/BP in US editions). So far, great!

The biggest reason I couldn't use Android smartwatches (Wear 1.0, Wear 2.0 era) was that whenever I'd need it, I'd pick it up and find it out of charge
I'd find myself frequently turning it off (like during flights), to save battery
Just not a great experience that way

The Watch Pro 5 (I am using without LTE - I rarely go out without phone, and when I do I do not need calls/sms) can run for *more than* 3 days on a single charge!
Not near the 1 week range of a Fitbit, but you need not carry charger for an overnight trip at least.

Plus, now with features like ECG, body fat %, BP reading, stress reading, and much much much better automatic activity tracking, I think the Watch 5 finally makes a case for Android Wear watches.
That said this is probably the only usable Android Wear device.

Also no comparison between Galaxy Watch and Apple Watch because you have to pick the one which ecosystem you are in. Neither the Samsung nor the Apple can be used with a phone of any other brand
That said, the Watch 5 Pro has a much longer battery life than Apple's latest Ultra