The fitbit users already have "google heath coach" in the latest googlified version of the app.
And https://www.reddit.com/r/fitbit/ is full of commentary on how laughably crap it is.
I'd pay more to avoid this kind of "feature".
Battery life Time Vibrating alarms Sleep/Step tracking
Happy with these (and the ux and price)
Find my phone: because sometimes you'd rather not spend 5 minutes checking where in the house you might have put it down, so making the phone beep saves time.
Tap to pay: I live in a big city. Serious crime is low, but phone snatching is common. Paying without even taking a wallet or phone out of your pocket is ergonomic. People use it for public transport too.
However, Tap to pay requires payments infrastructure and certification. A watch that does it will always come from a larger corporation because of this. e.g. Pebble watches do not do it.
The "AI health coach" is pointless shovelware. The inevitable "AI feature" that no-one asked for. This is a failing of larger corporations too, so the sweet spot (if it exists) would be NFC without "AI health coach".