A new report from the NBD Group shows that smartwatch sales in the US increased by 51% from November 2017 to November 2018. Wear OS only accounted for a maximum of 12% of all of these wearables sold. The rest of the sales were those from the top 3 in this market: Apple, Fitbit and Samsung.
https://www.notebookcheck.net/Is-Wear-OS-in-trouble-About-88-of-smartwatches-sold-in-2018-ran-proprietary-software.407711.0.html