Eskom hollowed out its engineering core with the BEE transformation wave.
That is not the natural order of handover at an engineering company. The old guard are supposed to train up and mentor the next generation of engineers, but that process was completely disrupted.
So even if they brought in loads of senior, hard working engineers, it would be years before that change would ripple out in the company and have a broader effect. This isn't just a matter of being a good/senior engineer, it takes years to skill up on the inner workings of complex projects as an outsider. This would be rebuilding their engineering core from scratch.
The seniors with the knowledge of the inner workings of Eskom and could make progress quickly were booted out and have moved on! You think they are going to come back to working for peanuts in a hostile environment?
Basically, the whole way Eskom has been handled is a complete clustervark.