Whilst Apple’s iPhone sales might be falling for several reasons, the Apple Watch sales are trending in precisely the opposite direction with a near 50% increase in their Wearables business for Q1.2019.
Source: CNET and others
The Apple Watch is BY FAR the biggest selling smartwatch. Ever.
Watch out Garmin, the Apple Watch is getting better every year. By 2021 you might have a problem on your hands…I mean, wrists.