I have noticed that as a result of the vast ecosystem of open source software, web application development has become extremely rapid, to the point that a person fresh out of college can, in a few weeks become a productive backend or frontend developer to the extent that they can compete with their more experienced colleagues on delivering projects in time.

Is this situation unique to my company or is this true elsewhere as well? What can a senior engineer do to ensure they don't become irrelevant and replaced by cheap freshers?