It takes 1 to 3 years to train new generic skilled grads on average.
A company initially typically loses $35k to $140k in resources to train a Junior to be minimally useful. Thus, most ponder if a hire is going to have a career long enough on a team to offset that liability.
https://en.wikipedia.org/wiki/Dunning%E2%80%93Kruger_effect
In general, entry level gigs have a narrow scope of skills for many reasons, as managers know people plan to jump ship sooner or later. Staffing agencies have a feed queue for these roles in a large firm, and simply maintain the churn.
Good luck, =3