You literally stated "most people have gotten off of FB." Your citation shows it shrinking by < 10% for gen z and millennials, stagnating for gen x, and increasing for boomers. It's similar in my circle of friends but you can't discount the billions that still do use FB daily worldwide.

You stated more than a third of the US has Airpods plugged in most of their waking days. And again, I say this as a guy who owns a pair and sees them in the workplace all the time. < 50% of my team has them.

But 1. they don't wear them all the time. I'd wager < 3 hours per person. Mostly during commute and gym. 2. I'd say wireless headphone usage is increasing in general, I don't see why you have to exclude non Airpod users? 3. Most importantly, you can't build apps on a platform that doesn't support apps!