Reincarnation is for sure one of those interesting existential questions we should grapple with. I’m a little bit of a fence sitter on it which is easy because we aren’t committed one way or the other.
In some respects I think we reincarnate but the issue is where and how. I’ve listened to a couple interesting guys Billy Carson and Jason Jorjani and their thoughts on the subject are that we leave the spiritual plane we are in now when we die and we have the chance to go somewhere else if we can. Unfortunately these days there’s a lot of demonic forces that make it far more difficult for us to move onto the next step in the spiritual journey, where we would go to another dimension or realm not the Christian Heaven stuff but to continue our journey to where we should go. We are blocked and therefore we will often reincarnate somewhere here.
A lot of this is based on ancient Sumerian writings, which have a lot of knowledge in them on things we’ve forgotten. It’s pretty fascinating stuff!
I think it's always been the case that there's been 'demonic' or other forces that cause us to behave badly or to make the wrong decisions so that, accordingly to ideas about reincarnation, we need a theology or philosophy that says 'behave badly and you will come back as a slug' or 'dont do the right thing or you'll go to hell'. Perhaps 'these days' we have less people subscribing to religious ideas that would moderate their behave or perhaps we just have more people or we have the media to inform us and make us believe their are 'demonic' or equivalent forces.
Bottom line is we seem to need to think there's a reason to behave well for some after this life reward, rather than having an intrinsic motivation to be a good person in this ONE life.
Sumerians were just philosophising like human have over the centuries - that's the rub right - no one can be sure.