I've had Fitbits for years but I'm probably never buying another one.

The main thing keeping me locked into the Fitbit ecosystem was the social features - my family are dispersed around the country and all have Fitbits, so for years we did the weekly step challenges as a bit of friendly competition and a vehicle for staying in good contact. The competition made a genuine difference to our behaviour - especially for encouraging my parents to stay active in retirement.

Then after the Google acquisition they killed off the challenges on spurious grounds. It's generally suspected this is part of a drive to gradually kill off the Fitbit brand and drive people onto Google's own Pixel watches. Now Fitbit's USP is gone and so I'll probably just get a Garmin next time as people generally think that's a better product.