Why not just turn off the notifications on the watch, so you can enjoy it for what it's good at? I won't give up the functionality, but I am extremely selective about what it notifications it can put in front of me.
I do wear it for workouts, but once it's closer to end of life will replace it with something dedicated for workouts like a Garmin that holds a charge for 14+ days.
Check out the Quantified Scientist on YouTube, he does some interesting testing on health devices.
But as you say the always-on ECG of a strap like Polar H10 always going to provide a superior result.