Apple sold ~50M Wearables in 2018 ($10B wearables revenue ÷ $200 ASP) vs ~200M iPhone sales.
So, less than 25% of iPhone users probably have Airpods or an Apple Watch.
Realistically, given that phones last multiple years, the number is closer to 10%.
I don't know a single person that owns neither, and I know at least a couple dozen people with an iPhone.
4 out of 6 people in my cube farm own airpods. I see them everywhere. These things are incredibly popular with the under 35 demographic.
I do occasionally see people with AirPods, not so sure about Apple Watches though.