This line has been repeated ad nauseum but I have never seen any backing data. Why would salaries decrease? Software development, done well, is a highly technic

This line has been repeated ad nauseum but I have never seen any backing data. Why would salaries decrease? Software development, done well, is a highly technical craft. Maybe for the first rung of developers it'll go way down but those Staff/Senior Staff I would expect to still command large salaries.