It's less of a big deal than I thought it'd be.
I switched from a Garmin to an Apple Watch - which has less battery life - for some development work I had to do and it turned out I barely noticed.
Charge phone, charge watch, charge headphones just became a nightly checklist.
But unlike headphones and your phone, you want to wear your watch at night to monitor sleep
At least that's a major selling point for these smart watches
I guess it's dependent on what you're using the watch for. I like the sleep tracking and various overnight metrics. Find keeping an eye on RHR and HRV is one of the best early signals for overtraining.