The issue with Toyotas in the North American market (ever since we lost the 1 Ton Hilux) is available payload. We sacrificed that in the name of comfort when the Tacoma arrived. We Americans want our ride comfort! Consequently, the first number you are likely to be over when towing with any Toyota truck or SUV is payload.
What’s extra odd about it is Toyota’s printed door jamb numbers are estimates. People have taken their bone stock 2nd and 3rd gen Tundras with a full tank of fuel to the CAT scales and found that their curb weight is further away from GVWR than the door jamb says it should be. Instead of 1300lb, it’s 1410, for example. One guy’s 3rd gen had over 200lb more available payload than the “occupants and cargo should never exceed” number when he went and weighed his truck.
The GX550 might be rated to pull 9k lb, but is the door jamb number anywhere near what it needs to be for me to pull even 7k and have my family in the vehicle, too?
This is the problem, and I will shame exactly no one who is mildly overweight (read: within all numbers for towing except GVWR in the tow vehicle).
I would buy the Qatar poverty pack triple locked 300 with cloth seats and no sunroof in a heartbeat, especially a non-turbo model. I think they sell for the equivalent of $55-60k.