We've never been there

We don't know what's there.

If these tubes exist, we don't know what their properties are, or what it will take to exploit them.

These alleged lunar resources have never been proven to exist, and even if they do exist, they have not been located or mapped.

Even if these resources and structures exist exactly as you've outlined them here, it will still take an enormous effort just to survey the area and set up the infrastructure to develop them.

Read about the Panama Canal. Before the first shovelful of dirt was moved we had to drain the swamps and kill the mosquitoes so we could build the towns where the workers would live who would unload the ships that were bringing in the steam shovels. And so on. And so on. Digging the ditch was chicken shit compared to all the prep we had to do first.

Remember Arthur C Clarke's "The Deep Range"? We were going to mine the ocean floor and live in domed cities on the abyssal plains, farming fish and plankton and algae to feed the world. That's not impossible either, but it still didn't happen, and its a lot closer than the moon.

Remember how orbital satellites were going to pay for themselves with all the zero-g manufacturing we would be able to do? The perfectly spherical ball bearings? That never happened either.

Just because something is not impossible doesn't mean it is inevitable. And it certainly doesn't mean it will be profitable. Think, fission power, the supersonic transport, flying cars...its all space groupie wet dreams. We abandoned those things; not because they were impossible, but because they weren't profitable.

Some things are just too complicated, or too expensive, or too dangerous. And some things will turn out to be unnecessary because we'll find easier, cheaper and safer ways of doing them, ways we can't even imagine right now.