I imagine there are probably some situations where close to zero (but not actually zero) torque is fine, where this may be useful. I don’t know what those are, but something that maintains a nearly constant speed it’d be OK. Once it’s up to speed you may not need much torque to keep it there. You can just slowly add or harvest energy from it. Maybe a flywheel or something? But yeah, this is certainly not replacing gears for most purposes. It’s next to useless in most applications for gears.
I imagine there are probably some situations where close to zero (but not actually zero) torque is fine, where this may be useful. I don’t know what those are, but something that maintains a nearly constant speed it’d be OK. Once it’s up to speed you may not need much torque to keep it there. You can just slowly add or harvest energy from it. Maybe a flywheel or something? But yeah, this is certainly not replacing gears for most purposes. It’s next to useless in most applications for gears.