To me, and I guess to a lot of other users, it should be an amazing opportunity to layer different Amps on top of each other.
For example: there is a great Plugin with lots of Distortion but the Attack doesn't cut through the Mix and you would like to have a much more percussive and fat character to those transients so you want to layer a less distorted and more dynamic version of that sound or another over/under it.
Of course you could "simply" double the track but that always comes with a lot of "wash" so that the sound gets less definition.
Of course there are plenty of other creative scenarios possible.