Maybe they do. Maybe they don’t. Unfortunately, by making the statement that “People really do attain enlightenment,” etc. you’re framing it as a scientific problem. You’re stating this isn’t a matter of FAITH, but a matter of FACT. Elsewhere you wrongly claim that science takes a position on such questions. It’s actually agnostic. I think what you mean to say is some scientists have taken positions on these questions. Some religious people have taken positions on these questions too, obviously. People take positions on all sorts of things for a variety of reasons.
Regardless, science itself merely states that if something is, in fact, “real” then it is at least in principle confirmable with evidence. Since no evidence has been presented for past lives or angels that is either testable or otherwise confirmable, whether these things “really” exist or not cannot be determined. As to their non-existence, evidence can’t be presented for that conclusion because you can’t prove a negative. That said, I continue to fail to see why their reality or lack thereof has anything whatsoever to do with having truly powerful and meaningful experiences, whether we choose to call them spiritual or not.
No one that I’m aware of seriously questions that people have what they define as spiritual experiences. What science and most contemporary philosophy would point out is that having an experience is not, by itself confirmation of how that experience is interpreted by the individual having it. Thinking you were abducted by aliens is not evidence you were abducted by aliens, no matter how real the experience may have been to you. Maybe you were really abducted by aliens, maybe you had a very vivid dream or hallucination, or maybe you were abducted by someone dressed up as an alien. The fact you (or I) interpreted what for us was a very real experience as an alien abduction (or whatever) doesn’t actually function as evidence that our interpretation of it is correct. Each of us daily experiences the earth as flat and watches the sun “rise” and “set” every 24 hours, but our experiences of these events is quite different from the reality. Our mind is notorious for playing tricks on us regularly.
You reference the Buddha. It’s worth remembering that there were some questions he refused to answer. Among them was the existence of what in the West is commonly referred to as a soul. It’s existence or not simply had no bearing on his teachings or upon what really mattered. When religion insists upon a factual interpretation, it ceases to be religion (or spiritual) and becomes dogma, ideology, and ultimately a matter for scientific and historical analysis. If it wants to remain meaningful it should follow the Buddha’s lead and stop insisting on answering questions that are ultimately of no consequence. Spiritual experiences simply are not dependent upon things like the existence of angels. They are personal experiences by definition and will occur whether angels are real or not.
If the story of Noah’s ark is a metaphor then we can all learn something from it no matter how we define ourselves in relation to religion/spirituality. But if it’s presented as a “real” historical event and the flood it was built to rescue wildlife and humanity from is offered as an explanation for the formation of the Grand Canyon, it becomes nothing more than the butt of a lot of jokes about the impossibility of getting that many animals on a boat to ride out a catastrophe that requires us to come up with a lot more water than has ever existed on the planet. Only by accepting that meaning is subjective and some experiences are ineffable can religion/spirituality take a form that allows for personal/collective significance. It seems to me you’re trying to eff the ineffable. Time to watch (or rewatch) Bill Moyers’ interviews with Joseph Campbell. Myth is poetry, and to talk of poetry as being either “real” or “false” is to miss the point. Every time someone insists it’s “real” they force scientists, philosophers, and historians to step in and demand evidence. Don’t blame the scientists when you’re the one that put them in that position.