I'm still not convinced, and even the assumption of an "ultimate reality" is tenuous and speculative.
I'm not sure how that's actually a question. Do you think when someone speaks of ultimate reality that this is something separate to this reality? What best describes this is that it excludes nothing, but includes everything. Isn't even the pursuit of M-Theory itself seeking that, only from just a physicalist point of view? What exactly do you imagine people are saying when they speak of ultimate reality, or ultimate truth? It would be helpful to hear what you imagine others mean and speak to that.
Then there are different beliefs around about what "ultimate reality" might be, but these views are often contradictory, so they cannot all be correct.
Yes, the beliefs may be contradictory, and no one is arguing the fingers are all correct. I've always used the metaphor loosely, not strictly speaking. I like many paths from the foot of the mountain analogy better. Many times those paths coming up from the foot of the mountain out of necessity have to turn back on themselves, go down instead of up, or maybe into the mountain in a tunnel, etc. Someone taking a look at the paths may conclude they are not all pointing to an ultimate peak. And that may relatively speaking be true. But the peak still exists. The mountain still exists. None one is suggesting the paths are identical, nor that they are straight lines and they all look the same.
Again, what I am saying is that all paths, all truths, even contradictory ones, are part of this whole. The fact of the paths themselves speaks of commonalities. Let me put the fingers pointing metaphor in another light. Some fingers are white, some are black, some are yellow, some point up, some point down, some point left, some point right. But they are all fingers. They are all pointing.
Now, let's take this metaphor of the moon and say that it is this ultimate reality. Ultimate reality does not exist in a place. It is not localized. It is everywhere, at all times, in all places, everywhere and nowhere. So all the fingers are always pointing to it. Don't literalize the moon metaphor. And that, literalizing metaphors, is exactly why I had that lengthy explanation of language as metaphor before. You miss what it points to.
Theism and atheism in particular look like contradictory rather than partial views.
Yet the theist and atheist standing under that single bright moon see no contradiction. I know from experience this is true.