The Short Version
Google's Fitbit migration left kids' watches non-functional for parents using Family Link, forcing a choice between device access and account supervision.
Google owns both the Fitbit platform and Family Link, the tool parents use to supervise kids' accounts, yet the Fitbit migration broke kids' watches for families using both. Parents now face a choice between a watch that works and an account they can monitor. Google had every resource to prevent this and simply did not.