There is nothing supernatural or other worldly about all this.
Given that it doesn't demonstrably interfere with this world in any measurable way, then if it's not otherworldly it doesn't exist at all.
It is just a hierarchy of needs that is built into the system. Base needs, social needs and intellectual needs are in that order. Even in this there will be differences between person to person.
So far, so Maslow, but then you go and upend the whole apple-cart by suggesting that the point isn't to build a life where you focus higher and higher up the hierarchy of needs, but where you actively try to drop off them bottom because...
It is about self development and not about any reward in the next life.
What next life? Even if there is a next life, won't we have to try to not live that one either... in which case what's the point? Why go through a sequence of increasingly tedious lives, each one getting less and less rewarding for the opportunity to not enjoy the next one? At least Christianity suggests that the next life they can't evidence might be better than this one.
O.