The "this is all so great (though, I mean, at least as Lovecraftian?) that there must be something behind it" or "Buddhist practices do help you find meaning (and Pure Land and saviors and all the stuff about wild miracles are allegorical or else wrong-but-maybe-useful)" is the sort I can understand, actually.
It's the leap from there to "this specific set of stories is right—as in, actually true, or at least much of it is—and the rest are wrong. I've not picked this one to follow because the moral teachings and practices give me comfort and little offense, but because I think a large part of the specific supernatural episodes the faith considers true are true, in a real, actual sense". Supernatural angels and god(s) themselves really actually do stuff in real life—maybe now, and certainly in the past—that kind of thing.
There seems to be a big leap from a feeling of wonder at nature (essentially, unitarians as I understand it) and structured organized religion.
More specifically: why can't you pick and choose? Christianity has hundreds of sects, each of which adds or removes beliefs both big and small. Belief the Pope is infallible being the most obvious one that caused a lot of bloodshed.
This view agrees with what you described up until "if so then some religion has to be true": it affirms that we have reason to believe in a creator (and in some accounts, in divine providence of various sorts) but doesn't expect a divine revelation, or doesn't endorse any claims that we've received one.
I remember that Descartes argued that the creator was logically required to be benevolent and that part of that benevolence would then entail getting in touch with humanity and letting us know something about the divine nature. But other thinkers took various other angles on this, including the idea that the divine benevolence is already complete even without revelation, or that revelation occurs in a non-public or even incommunicable way, or still other possibilities.
Atheists and deists have both been very preoccupied with the idea that different revealed religions are all extremely plausible to people who are brought up in or around them (in modern times, even different schisms of revealed religions have this characteristic). In the deist account, this might be a reason to doubt that any of them is uniquely intended by the creator to be a revelation to all humanity, since which one people believe is for almost everyone a matter of luck. (Even if one account of revelation is more compelling than others, most people will never have the social conditions to verify this for themselves.)
There are lots of theological accounts about why God might allow only some people to discover the true revelation, but a deist (and atheist) alternative is that it's also reasonable to think that that wasn't God's plan.
Of course anyone who thought their religion was made up by a human wouldn't really believe it. So this won't convince anyone either way.
What I can't understand is atheists who balk at the possibility of any kind of god, but happily entertain the notion that we are in a simulation. What exactly would be the difference in a created reality and a simulated reality?
I know that might come across a bit odd, but it's refreshing to actually try to understand other viewpoints and to do so inoffensively.
To me it’s a self evident miracle that any kind of universe exists, not to mention that there’s life in it, and even more amazing that the life can observe the universe, explore it, and enjoy it. To me something had to cause all this, and if so then some religion has to be true. If some religion is true then you can’t pick and choose the parts you like and discard what you don’t.
I agree that many of the most powerful religious leaders don’t actually believe everything they teach though. Religion is a powerful tool to get people to do what you want.