I agree it’s weird to describe one theory as “closer to truth” than another if you’re talking purely in the abstract, since obviously we don’t-and couldn’t - have access to the final Truth with which to compare them.

But we can say that certain theories allow us to do things that other theories didn’t. Science’s whole pitch is that it works. And if an idea lets us do more work than another idea, what does that make it if not “more true”?