There must be a reason everyone does not have AWD.
Because Herbst built an AWD truck about 20 years ago. They campaigned it for several years, and it was very successful, winning a lot of races. But they didn't think the AWD was worth it, so they abandoned the idea and went back to 2WD.
Geiser built an AWD truck many years ago too (probably 5+). Like the Herbst truck, it did not set the world on fire.
AWD has been around for a long time in TT. It's not a new invention.
That said, the portal front hubs are new, which allow more wheel travel. That's a significant advantage over the non-portal designs, and one of the reasons why the Mason truck really caught on.