A simple sanity check before deployment might simply check that everything loads correctly. As you know, use does more than just load. It actually executes code, in some cases. If the environment has changed, the config has changed (as it often does when you go to production), just loading a module might break.

But don't you see that all use_ok does, is allow the test script to continue when the use has failed. It doesn't test anything extra. It doesn't tell you any more. It doesn't verify exports, or configuration, or tell what piece of code failed. Indeed, if any warnings or errors are produced that might tell you what failed and why, it hides them from you.

And, unless you are testing more than one module from that test script (which I assume no one does), there is nothing else useful to do, because if the use failed, none of the other tests are viable. Literally all you've done by using use_ok is allow the running of further tests that cannot possible succeed. Oh. And allowing the harness to count more imaginary numbers.