What do insurance companies do with totaled cars?

I have a car that was damaged in an accident. The other person was 100% at fault and everything is through their insurance. The accident in my opinion was very minor and I strongly believes that the car can be repaired. The adjuster from their insurance company came to the auto body shop and deemed the car totaled. Again, I very much disagree with their opinion. The car is leased and apparently the exact make of the car is not that common, making it more valuable. I believe that the insurance company is being dishonest about the evaluation of the damage and cost of repair so that they can get the car and either sell it for parts or take ownership of it, fix it, and sell or die to the care being hard to find. I also think it’s possible that the auto body shop could have over estimated the cost of repair and be in cahoots with the insurance company so that when the insurance company sells the car, the shop could get a percentage of the sale. Those that have experience in the auto industry, do you think any of this could be a possibility? I strongly disagree with the instance company evaluation and decision so is there any way to push back? Thank you!