That "need" is not as a helper but a cheap way to train the next gen senior which by the time they are senior know the ins and outs of your company's tech so well that they will be hard to replace by an external hire.

If your approach to juniors is that they are just cheap labour monkeys designed to churn out braindead crap and boost the ego of your seniors then you have a management problem and I'm glad I'm working somewhere else.