Reincarnation was one of the ideas that seemed like a religious metaphysic that did not correlate with Buddhism's minimalist methodologies. The Dharma is a way to move towards enlightenment, that is all. If believing in something helps that, OK, but mostly understanding that everything is impermanent is more likely to help.
Conditionality has a funny psychological effect. If you think about causes and conditions long enough you can imagine yourself as everyone on the subway. You can see in their body language, how they are dressed, what they are doing--their whole being. I have been everyone and I will be everyone.
Every day we wake up is a new rebirth. But that is not what they thought in ancient India. And my above metaphor might not be what they meant--empathy into all existence.
The Wheel of Life is a specific take on conditionality. It leads you through how life is perpetuated. The gap between sensory input and what you conclude from it is where all the mistakes are made.
Was the Buddha's recollection of past lives an opening up of realizing conditionality? Did it give him confidence to think he'd been working on enlightenment for aeons? It's the whole of human evolution that has been working on enlightenment.
I can't help but think of Forever War and Forever Peace. They have created robots that fight for you, but being connected to your platoon leads to enlightenment, so they get you out quickly, you can only work in short shifts. Would we all be enlightened if we were connected deeply with our minds. That is the hope of empathy.
Analayo is pointing out that the Buddha realized past lives in his book. Realizing past lives is a step in the progression of the Buddha's enlightenment. Analayo wrote a book about Reincarnation, and in a talk I watched, he talked about little kids who recite the sutras, though they can't even read and don't speak the language they are reciting the scriptures in. His idea is that probably only reincarnation explains this phenomenon. I'm not convinced. I'm more convinced that as the Buddha neared enlightenment he remembered past lives. In my mind that was an insight about conditionality and my experiences on the subway that I could imagine all these lives. I can imagine being Caesar or even Trump's reactive arrested development.
The short upshot is that I feel like reincarnation is less unimaginable.
More of a problem in modern times is believing in moving towards enlightenment is possible and significant.
I met a Tibetan Nyingma Buddhist in my neighborhood. I was so excited.
Reincarnation was a big reason Stephen Batchelor turned from Tibetan Buddhism to Korean Buddhism, and later developed Buddhism Without Belief.
Conditionality is the thing.