Laser printers produce containers of waste toner. This is full of paper fibers, filler from the paper surface and sub-standard toner particles, so isn't reused in most printers.
In many instances, it isn't required that the print quality is pristine, it just has to be 'good enough'.
a dedicated printer for such draft output, for use in large office environments and organisations. A preliminary step would accept waste toner, sort and filter out the toner particles.
The printer itself would be optimised for the recycled toner, and would also ideally be able to print onto the second side of used paper*. (It would be able to orient and reject paper itself, as a preliminary step for that.)
* It may not be possible to re-use paper originally used for laser-printing, but ink-jet paper would be fine. Laser printed paper could be cross-fed to ink-jets of course.