That's a somewhat different question. Resale of the loans to the secondary market adds in it's own effects on the decision making. So when the GSEs decide their AVM might be sufficient to purpose for a certain percentage of loans that affects the demand for appraisals at the lenders.
One big advantage using fee appraisers has over staff appraisers is that the use of fee appraisers is scalable according to the volume levels. The lenders aren't paying for hours that aren't being worked and fixed overhead that isn't being used productively.
If a lender is doing 100% of their appraisal work by staff that can create problems for them. When the volumes lag you end up with a roomful of unproductive appraisers sitting around and competing for the fewer assignments that do come in. That goes on for maybe 2-3 weeks before the lender starts laying people off. They can't carry employees who aren't producing. Not for long, anyway.
That's how I got laid off twice by the same bank. They laid the majority of their appraisal dept off during a slow down and rehired me 6 months later when the volumes picked up, only to lay me off again when the volumes lagged. Except the 2nd time I was better prepared as a result of keeping a side hustle going by doing split fee work for a residential fee shop. After getting laid off the 2nd time that's when I struck out on my own - by necessity, not by plan or ambition. I learned then that - WRT appraising - corporate employment doesn't necessarily result in security.
