I want belted gearbox on any type of bike, and for such a bike to be affordable in my area

I’d love my fatbike to have both, belt drive and a gearbox. I barely even bother to adjust the derailleur anymore since I’m constantly banging it everywhere anyway. Gearbox would also give more clearance for 6 inch tire on the rear. Some innovation on the brakes section would be in place too since disc brakes don’t seem to like water and mud but mine are getting plenty of both.