AirPod Degradation?

I’ve owned a pair of Airpods for 2+ years now. Over the last few months, I’ve noticed that when I have the iPhone in my pocket, the airpod audio will drop out. I have to take the iPhone out of my pocket and hold it closer to my ears for the audio to play without interruption. I was hoping the new iPhone 11 would solve this issue, but it started happening today with the new phone. Is there something that happens over time to the bluetooth radio signal?

It might be a battery issue? lower power means lower output?