It may be that this procedure makes sense for a car that has gone well past its oil change interval.
Nah, it’s a “solution” for a problem that does not exist.
Another that comes to mind is the mechanic who suggests that when it comes to ATF (automatic transmission fluid), “one type fits all“ and the manufacturer’s recommendation is of no interest.
While I agree that the manufacturer’s recommendation should be considered, it turns out that there is modern synthetic transmission fluid that is quite suitable for the great majority of cars.