The fields of science and IT are constantly evolving. Just when we get comfortable, things change, forcing us to create new theories that drive new ways of doing things. For example, before the germ theory of disease was developed in the late 19th century, doctors thought disease was spread by miasma or “bad air.” Sounds ludicrous, but this was a reality at one time.
There are IT practices and methodologies that appear just as outlandish today. For instance, remember the practice of backhauling all internet traffic to the corporate data center via expensive MPLS lines and VPNs? With the advent of cloud services, routing traffic to the corporate network seemed as absurd as the idea of a flat earth.