They do actually. It sounds like the problem is that people are charging their battery banks using the charging ports at the seat rather than just plugging their devices in. Must be very jewish. "I paid for this seat and it's got a charging port, I am going to charge my battery bank for the $0.23 of electricity it COULD cost me if I was at home.
Hell, they could do that in the airport before their flight. It has been at least 10 years since damn near every airport had free places where you could sit and charge your phone while waiting for your flight.
With that being true, you should have a "usb condom" since who knows what the hell is lurking in those charging ports. Basically it blocks all data and only allows power. It won't work for some stuff but some of the OSS hardware can "fake" being hardware that won't keep you from charging while it is fully "read only" and can't be flashed/modified/etc.
Its a fucking pain in the ass.
I never considered that, then again, I have only used actual AC outlets with the block that my USB C plugs into. Thanks for the heads up.