detailed information in 10 seconds. The appraiser just takes 3 different swimming pools and says $25,000 regardless of what the pools actually are. A view is worth $10,000 ect.
A sales database can tell if a property had a pool or view and make the adjustments the "expertise" of the appraiser is unnecessary.
And lets not pretend that lenders are smart or do a good job of calculating risk under the current methods. The effectiveness of an appraisal in reducing risk would be increased significantly if the appraiser didn't know the sales price.