Earlier today Logitech announced their first new trackball mouse in almost a decade, incorporating user feedback from the last ten years. The MX Ergo has been modernised with DPI-like adjustments and software that allows switching between multiple computers.
https://www.notebookcheck.net/The-Track-is-back-Logitech-resurrects-their-ergonomic-Trackball-mouse.247118.0.html
I guess they could harvest the energy from the moving ball (a user moves the mouse a lot right?) and they could make this to last forever.
It's supposed to be ergonomic, not a workout. You can only harvest energy that goes in so that means more resistance to movement.