Because there are thousand of PEs across the country and eventually if a job requires 100x less time to produce, PEs will just be rubber stamping stuff after a thorough final review. My firm has like a dozen electrical PEs and we all spend the vast majority of our time in coordination meetings, reviewing small details, and working on drawings. If all I have to do is spend a few hours checking something at the end, they don't need all of us for that anymore.