Is there anything nasty in a standard wired headphone though? My impression was that basic electronics are much easier to dispose of than lithium batteries.
No, because I'd have to swap it out if I wanted to use a different device. As my second paragraph ays, having to swap it out frequently is a downside compared to my client device having a standard socket.
The headphone has a mini-XLR to 3.5mm connector built in. If it fails it's easy to replace. If the client device supports the standard 3.5mm connector it doesn't have to give a shit that the other end is XLR on IntelMiner's headphone (or in the case of my own headphones, 2.5mm for one set and 3.5mm for the other).