I’ve had to touch the derailuer on either of my MTB a grand total of once a year when I give them a once over for maintenance, or when I eat dirt and rip them off the frame - not the drivetrains issue there though, purely rider skill issue.

It rather tweak a cable once a year, or heck even a few times a year than charge a battery every few weeks.

I was assuming a box that would mount on the rear triangle, but no. Threads straight into the derailuer in a perfect position to rip it and the derailuer off in one go making everything useless.

Oh, and its more ewaste. Cable shifters work perfectly fine, I don’t understand the general obsession with adding more electronics and batteries to charge to a bike.