Most companies provide far more corporate training avenues at senior positions that at entry level ones. This is in stark contrast to the actual need which is felt more acutely at supervisory and entry management positions. There is a major lag between being an employee with being a manager. This transition ensures people make mistakes but only learn using trial and error in the absence of formal channels. This anomaly is due to three main reasons. First of all, training budgets are approved by top management and thus training managers pitch sessions more suited to them in order to get their budgets approved. Leadership development is any day a more fashionable term. Crucially, the top end of money, influence and intellect resides at the higher echelons. So naturally the best of trainers tend to focus more towards that level.

Source: https://hbr.org/2016/06/why-do-we-spend-so-much-developing-senior-leaders-and-so-little-training-new-managers