Do they block outside sound though? AirPods do and the trouble with that is you’re also trapping air in with your ears.
And the air being trapped close to your skin will inevitably be a different temperature to the air on the other side of the material. The temperature gradient creates condensation. It’s inevitable.
Assuming you want good sound isolation* the solution isn’t to avoid condensation, it’s to design it so the condensation forms somewhere that it doesn’t matter.
(* AirPods sound isolation is so good they have a microphone on the outside which, if it detects a fire/eathquake/etc evacuation siren, will replay that sound with the headphone speaker)