Comment by dcchambers

When companies stop hiring juniors it completely kills the employee leveling process. It all but stops the creation of skilled senior employees.

You say you can just hire from outside the company - but what do you do when there is no one left to hire because the talent pool is completely drained?

Abandoning the junior employee will slowly drain that talent pool until there are no seniors available to hire, the "just hire from outside the company" plan doesn't work any more.