so train them
Many companies that have already made the mistake of hiring too many juniors in an attempt to deal with the shortage, and have suffered the consequences (huge drops in quality and productivity, and in the worst case, seeing the experienced seniors they did have walk away frustrated).
Where education fails, major companies like Google and Facebook should take the responsibility for training juniors. Instead they spend their fortunes strip-mining the market.
Because that makes about as much business sense.