If you look into it, you’ll find that something like a Wrangler Rubicon can actually produce more torque thanks to crazy low gearing. It can only do it at speeds so low that it is only useful for off road rock crawling at a walking pace, but it does it it with drive shafts and differentials that aren’t very special and don’t explode.
There would also be some issues with the wheel flange if you want it to match the other axle and the brakes if you want them to continue to work.
But I think the biggest problem would be the the manufacturer worrying about you and me welding it badly and them getting a share of the blame when it comes loose on the highway and takes out a bus full of nuns and orphans.
I’ve seen a kit for a Range Rover that looked pretty cool.
But a generic axle swap means someone has to figure out how to adapt the suspension to the new axle. Which means custom mounts and some welding which might make the manufacturer worry about liability of the axle comes loose on the highway.
I think an eclectic motor sitting where the transmission used to be would be far easier for a DIY swap and cheaper.
I think I’d rather have a series hybrid like they’re using in the Edison trucks. Ideally it could also power some of my house during a blackout.