There are tons of vehicles vehicles than can drive off road without 4WD. Most of Rally racing has been done with rear wheel drive vehicles, and they're actually racing, not just casually driving. The reason a truck might not be able to handle it is because trucks are actually not set up well for it, unless they're loaded. Like the comment above says, the weight distribution is bad for it, until you load the bed. This isn't true for an EV truck. The weight is further back, so the rear wheels won't lose traction as easily.

Anyone who thinks they need 4WD to off-road doesn't know what they're talking about. Can it help? Sure. Is it required? Far from it.

Tons of cars fet drivetrain swaps! It's not bad, lots of kits out there and a little custom fab goes a long way. I have personally put hemis and 8hps in JKs, swapped an 02 drivetrain into my 87 YJ, have swapped a gas V8 rover to a diesel td5, have many auto to manual and vice versa conversion. Hell my co worker just put a Corvette engine in a rover backed by a 6 speed tremec and an adapter plate to the original rover t case. It's surprisingly simple! Hell u can even convert ice to elec pretty easily if u have the where-with-all!