The senior developers are busy making deadlines for products that should have been delivered moths ago, so they and their managers can't really afford "knowledge transfer".
A young employee is far more likely to fail in this kind of enviroment than someone with some experience.
I got my foot in the door by applying to an unpaid position and lying about my knowledge. They were looking for experience in a particular framework and I then learned the basics of it over the weekend.
I can understand the resistance to do this given that juniors are demanding well over six figures and the widespread recommendation to skip town every two years. Paying $400,000 to spend a year eating up a senior engineer's mentorship time and then getting a year of work taking tickets off the wall is not a great trade. I don't know how to square this circle.
Where I live, you can get 15 motivated and capable CS graduates for that kind of money.
From what I've heard and seen, anyone hiring a junior engineer is getting overwhelmed with applicants the moment they advertise it. Going up in experience level, the same places that are overwhelmed with junior engineers are begging for senior and principal engineers and are leaving these positions unfilled due to a lack of applicants.
Even at a very senior level, I've been asked to do some ridiculously sysadmin-ish stuff that I'm not good at, and I've seen more junior people loaded up with web/testing/devops/admin work to the point that the majority of their time is no longer being spent on what is ostensibly their job.
As far as I can tell... Google is still around?
take action, give 2 weeks severance, move on. both sides.
now, someone that turns into a problem after 5 years, that's on you. they weren't bad when you hired them, you made them that way.