Liftgate Problems

Hi,
I bought a brand new 2019 Sienna XLE. It does have a lot of miles on it now, 98,000. My wife does drive it a lot. But this shouldn't make any difference concerning the lift gate though. Right when it was out of warranty, the lift gate started kick back. Took it to the dealership and of course they wouldn't do anything about it. It was only 35 miles over the warranty. I started looking to see if I could figure it out. Well the sensor on the left side was barely touching the tail light, so the hatch would kick back. Also, the spoiler was not even with the body. It was higher than the body about a 1/4 inch. This caused the spoiler to hit the body and was rubbing the paint off the spoiler. Raising the other side of the gate with washers under the hinge did stop the sensor from hitting the taillight, but made the rubbing worse. So I took them off. Eventually, problem got worse and starting to leak water. I took it back to Toyota dealership, they quoted me 3,100$ to fix it!! I told them they were crazy! They said the gear assembly gears were stripped and it needed a new rod (it was loose). Also, it needed new sensors for each side, really? And it needed new strut rods that they were leaking, I don't think so. Does anyone have any suggestion on how to proceed? If I had gotten the extended warranty the repair would have been covered. I'm very disappointed with Toyota. Their quality control has gone down hill. Terrible. My wife won't buy another Toyota ever!