The Greeks thought truth could be discovered through intellect and logic.
Aristotle made fundamental contributions to topics ranging from pure logic (which he more or less invented as a subject of study) to the reproductive behavior of intertidal invertebrates.
Then we found that discovery requires experimentation and the scientific method.
What "scientific method"? What's that all about?
Once again, Aristotle more or less pioneered discussion of the philosophy of science, when he extended his ideas on the nature of valid inference and explanation to the question of what form successful science should take. The point being that the whole idea that there's a "scientific method" in the first place is philosophy.
But, alas, even for science the truth of God's existence, or not, is beyond its scope.
Yeah, I agree with that one. The scope of science is objects, events and their interconnections here in the physical world. I'm not sure what the word "God" means, but it typically seems to refer to some hypothetical divine entity that lies outside and transcends the physical world entirely. So by definition, it would seem to lie beyond the range of science.
So, given that even science can't address the question of God, why would one logically conclude that pure philosophy, which has a track record of zero successes in the real world
Do you use logic? Does science? Think about it.
And your phrase "real world" seems to suggest some kind of ontology, some theory about the kind of things do and don't exist. That's philosophy too. (You can run but you can't escape it.)
I'm not sure if philosophy is necessarily as restricted in its scope as physical science is. It addresses more abstract entities as well, such as mathematical objects like numbers.
But yeah, I agree that there's a major problem of how, if transcendental realms of being do exist, how human being like us could ever know about them and obtain any information about them. (That's epistemology, the theory of knowledge, and that's philosophy too.)
To my knowledge, pure philosophy has never correctly predicted anything.
Try to explain why you think that predicting things is important, without lapsing into philosophy while you're doing it.