I agree with this take in a steady state, but the process of building software is just that-- it's a process.

So it's natural for error messages to be expected, as you progressively add and then clear up edge cases.

Exactly: When you're building software, it has lots of defects (and, thus, error logging). When it's mature, it should have few defects, and thus few error logs, and each one that remains is a bug that should be fixed.