Some of these jhanas are incredibly powerful but they have an opposite, that being emotional and mental upheaval and the dark nights.
Essentially, I realise that there are valuable insights to learn from both their extremes but I find that delusion can arise as part of the mental upheaval (I thought I was in love with my teacher) now that I'm out of the delusion it seems so silly.
Buddha had mentioned in a few suttas (I can't remember their names) that jhanas are the way to nibana but was this within the context of who he was giving the teaching to?
As an example, the satipathanna sutta was taught to the kuru people because they already possessed a deep wisdom and an advanced ability to learn quickly thus, the teaching he gave was conducive to their ability to attain higher levels of realisation very quickly.