On the other hand, this is what mass adoption of wireless headphones will lead to, and it shows how ridiculously bad this is compared to the tried-and-true wire.
There are some BT devices that have poor antenna designs and underpowered transcievers, where the proximity of other humans — or even your own body — can significantly attenuate the signal. But this isn't a problem with the spec itself, and there's plenty of devices that have shown it's possible to do it right.
Considering that WiFi and Bluetooth both run at near 2.4GHz - I’d assume that areas with a lot of wireless networks could (and have in my experience) interfere with BT.
This wasn’t limited to 1 set of devices though. Tried it with my AirPods and a pair of NC Sennheiser headphones. Both cause issues when walking into busy (in terms of WiFi) areas.
aka public transit...