This is all my opinion based on my personal experiences in towing and talking to others who tow RVs and varying trailers.
First, a fact. The tow rating from a vehicle manufacturer is based on the vehicle having zero options in it. So a base model with no heated and cooled seats, leather, HD transfer cases, roof racks, 17" tires, etc... all of that adds weight to the vehicle and subtracts from the tow capacity. Also, its based on a 150 pound person in the vehicle with zero cargo. Start putting your family and friends in the vehicle with gear in the back and that also subtracts from the tow capacity of the vehicle. Start upgrading to 20" wheels and that adds more weight to the vehicle.
Because of the above fact, I personally live by the general rule a lot of folks live by that tow trailers and RVs. the 10% rule. Leave 10% of your towing capacity as head room and you can usually always account for the family and some gear in the tow vehicle without having to do the hard math. For example: my 2019 Silverado has a tow capacity of 9600 pounds. I have the LTZ model which has lots of upgrades. I also have my wife and a few kids with me when we tow as well as the dog, and all of our bikes in the bed of the truck. When I selected a new trailer recently, I made sure the trailers GVWR was not above 8640 pounds which is 10% less than the trucks tow rating. This gives me 960 pounds to account for the heavier options in the truck, the cargo, and the people we will carry while towing. The GVWR on our trailer is 7600 pounds, so I have 2000 pounds less than the truck is weighted for. Plus, we don't usually have more than 1000 pounds of cargo in the trailer, so with the dry wieght being 6040 pounds on our RV, I figure we have roughly 7000 pounds im pulling, leaving me with 2600 pounds of head room.
Now... personal experiences and talks with others lead me to have the following opinons.
Just because an SUV like a Tahoe or Yukon (short wheel base) is rated for 8000 pounds, I would not pull that kind of weight with it if the trailer is 30 feet long. That's a trailer that is two and a half times the length of that tow vehicle and a longer wheel base matters with longer trailers.
I see more and more people towing 5th wheels with half ton trucks. The RV market is very good at marketing "half ton towable" on 5th wheels and too many people are fleeced by this. Those 5th wheels are usually always assuming the dry weight of an empty RV and those weights are at the top of almost all half ton trucks' towing capacity. So if you don't like packing your R with anything other than what comes from the manufacturer, and you don't want to take anyone along with you, you may be OK. But then there's the fact that half ton trucks are not manufactured with goose neck or 5th wheel towing in mind. I would avoid this all together. I am not bashful when I see a half ton truck puling a 5er to wlak up and ask that person how it tows and how the truck performs. They all answer "great". But if I happen to see them on the road traveling, they have both white-knuckled hands on the steering wheel and are the slowest rig on the highway.
A truck or SUV with a V-6 will pull a 12,000 pound trailer. It can even pull it up hill. (All be it slowly). But, it won't stop that trailer safely, and you will wear out the suspension quickly which enhances the unsafe towing.
I'll end with this. If you don't put a lot of miles on when towing, by all means, go up against the vehicles limit on tow capacity. Towing 20-30 miles is not going to hurt it. But if you are going further than that, and traversing highways or thick traffic on the highway, you owe it to the other drivers around you and your passengers to tow safely.
2019 Silverado 1500
2020 Coachmen Freedom Express 29SE
Me, Wife, 5 kids, and a Doodle