> But I don't understand how the question "what is the purpose of X" can be anything but philosophical.

Again, my guess is that this depends on how much we know. Or, there about has to be a purpose. And eventually as we learn more there should be some clues about what that purpose is. So I'm wondering if we know that much yet?

A first little clue is the speed of light speed limit that so far seems to say that we are quite isolated from the rest of the universe. So, somehow having us isolated was deliberate. Then, what might be the purpose of having us so isolated?

Then there's the 3 K background radiation. That's one heck of a clue. What might be the reason for giving us such data? To answer, what can we do with it? If we note what we can do with the 3 K data and that seems really special, e.g., we wouldn't be able to do that without the 3 K data, then what is so special we can do with the 3 K data might be a clue for the purpose of letting us have that data.

There's the Heisenberg uncertainty principle. So, it keeps us from being as in an 1890 view of physics, mechanistic. We are stopped at that level by some dice rolling. So, why? When we see how that stops us, we might get a clue of a purpose.

All of that is very thin stuff, but maybe we are on the way to discovering enough to start to conclude what the purpose is.

One point is our existence and our abilities: First cut, how the heck to look at the basic physics and guess the chemistry, then, especially the biology, and, astounding, how the biology developed into us. That's some amazing laws of physics that let that happen, maybe ensured that it would happen. So, what the heck is the purpose of us being here, our existing? That is, we're the most special and amazing thing we know of in the universe. So, if there is a purpose, then it looks like we are a key part of it. So, just what the heck might be what we are to do with our abilities to understand the universe? Then, do we get a hint of the purpose from what we can do? That is, is the purpose the special stuff we can, or will be able, to do? For that if we look ahead, just how much might we be able to do? Build Dyson spheres? Okay, then what would that enable?

We don't see other planets flashing light signals at us from
their Dyson spheres. So, why not? Sure: There are other, better forms of long distance communications, and every planet with a Dyson sphere knows this. So, soon we should discover this better means of communications. So, where the heck to look for those better means. Then when we find them, what would that enable us to do in the universe that would be special? Communicate only? Or both communicate and travel? Or, if long distance travel is possible, then why ever bother to travel; just send robots and have them send back the communications so we can view it. Then does that communications give us a clue about a purpose; that is, suppose we could send robots and they would communicate back; what might we discover that begins to suggest a purpose.

Or, generally, as a meta argument, if we find some things that look really, really special that finally, with our development, we can do that seem to impact, explain, discover, reveal the universe, then maybe our doing that is the purpose of the universe.

I fully agree this is very thin stuff. Still I have to suspect that as we learn more, maybe 1 million years from now, we will begin to guess at a purpose.

Or, if there is no purpose, then this is one heck of a big show for nothing!