Another reason adjusters are forced to write “incomplete” initial estimates, from which the first payment is issued, is because they know they do not have to pay a supplement for the rest of the repairs until the vehicle is in a repair shop and disassembled, and waiting their approval (another delay on their part)
But sometimes people just take that initial estimate (incomplete estimate) payment and don’t repair the vehicle or just do a very minimal repair to make it driveable (which can only be done if the owner has title to vehicle because lien holders will not allow that) and when that happens and there is no supplement done by a shop the insurance company gets away with only paying a portion (usually small portion) of what they owe

they save millions of dollars over the course of many claims by doing that.
99% of the supplements we write in the shop is 2, 3, 4 times the amount of original estimate - truly
If you don’t believe me you go ask any number if shop estimators in you’re area & they will confirm that
Sorry bruh, again this is not personal toward you as you are just doing your job. But I started in this career on the insurance company side of this & these things I learned first hand and decided to leave to the other side. 24 years in this business, this is what I know