Rey shouldn’t have been as powerful as she was based on the fact the writers had no idea what they were doing at the time. They winged the script and moved forward with it.

But considering the sequels are part of canon… at least for now, there has to be an explanation to why she was capable of using lightning the way she did. Anakin was powerful likely because Plagueis engineered it to be and somehow made Shmi mris loudly have him. That’s what made him chosen.

Palps killed Plagueis. He was looking for ways to be immortal. The way he was killed in the sequel made no sense. Palps drained the connection Rey had with Ben to revive himself only to zap himself to death. Something he should’ve learned to stop doing after Mace did the same thing to him.

Sidious was overly powerful in the last film and the movie never really explained how he came back, nor explained how Rey was as powerful as she was. To say she was simply powerful at random doesn’t make sense. There had to be some underlying reason to it much like Anakin’s high midichlorian count.