There’s something about having two independent Bluetooth headphones that makes them much more than twice as likely to get lost. And I suspect that part of it is having both ears blocked and thus needing to take one out much more frequently.

Also there are a disproportionate number of tech people who have ADHD, and multiple small objects do not just have a high probability of getting lost, they have a virtual guarantee of doing so. Multiple times before they are lost forever.