Comment by shagie
I'm unsure about how long your career has been.
At Taos, there was a monthly training session / tech talk on some subject.
At Network Appliance ('98-'09), there was a moderate push to go to trainings and they paid for the devs on the team I was on to go to the perl conference (when it was just down the road one year everyone - even the tech writers - went).
At a retail company that I worked at ('10-'14), they'd occasionally bring in trainers on some thing that... about half a dozen of the more senior developers (who would then be able to spread the knowledge out ... part of that was a formal "do a presentation on the material from the past two weeks for the rest of your team.")
However, as time went on and as juniors would leave sooner the appetite for a company to spend money on training sessions has dissipated. It could be "Here is $1000 training budget if you ask your manager" becoming $500 now. It could be that there aren't any more conferences that the company is willing to spend $20k to send a team to.
If half of the junior devs are going to jump to the next tier of company and the other half aren't going to become much better... why do that training opportunity at all?
Training absolutely used to be a thing that was much more common... but so too were tenures of half a decade or longer.
Then it sounds like you need to train them and also pay them better. Most people just want to stay at one company and not do the grind, but the lack of raises, poor treatment, and much better pay other places is blaming juniors for your companies problems.