What's the point of putting him through surgery if they aren't going to change their ways in feeding him?

Exactly and if you go to a vet for the dogs whole life since he was a puppy then he says no to surgery you don't just up and change vets to get the answer u want you change his diet and help him lose weight. Not continue to feed him table food untill the day of surgery.

no I would if he was suffering I'd put him to sleep personally. the tumors will more than likely come back if he makes it through surgery and 13 is old ish for a dog. a lot of risks come with increased age and weight in a dog having surgery. so 3 vets wouldn't do surgery on this dog for a reason, they don't just turn people away from no reason usually there are some shitty vete

He's suffering from being over weight. He sleeps all day never gets up not very playful. The reason I ask is bc they scheduled him for surgery next week. They have known about this for months an had time to put him on a diet and all they do is feed him human food right from the table. I understand it's there baby. But he is 13 and as you can see very very over weight there previous vet refused to do the surgery so they switched to find someone who will. So they did two vets later. And he goes in next week.

No unless he is already suffering without surgery

Aww poor baby. :'( well it's either he dies from being over weight. or he will pass away during surgery. either way it doesn't look good to me. Unless you put him on a strict diet ASAP. then once he gets down to the weight he needs to be in. you can possibly take him in to have surgery to remove the tumors.

No I would not risk it