As one Subaru Crosstrek owner recently learned the hard way, it bears repeating that all-wheel drive is not the same as four-wheel drive. A Subie owner posted a warning letter they received a month after driving on Colorado River Overlook Road in Canyonlands National Park to the r/NationalPark subreddit. The letter notes that this particular road is restricted to 4WD vehicles only, and the Crosstrek is equipped with AWD, not 4WD. It also warns that they may face serious consequences if they’re caught taking an AWD car on a 4WD-only trail again.
If you have 4 wheels, logically 4WD is AWD. Why not just say you need to have a locking diff?
Subaru has x-mode for difficult terrain, which is different gearing. They also have hill descent. https://www.sportsubaru.com/subaru-x-mode.htm
Why would you want 4wd with wasted energy then you could have a symmetrival awd and get all the power to wheels that have traction, skipping those that don’t have traction?
I only see awd outperform 4wd when it comes to a subie, but other awd systems from other manufacturers are probably not up to snuff.