Sometimes the print statement is in untested sanity-checking error-case branches that don't have test coverage ("json parsing failed" or whatever). It's pretty annoying when those things throw, and not too uncommon.

Another case in C++ is if the value is templated. You don't always get test coverage for all the types, and a compile error is nice if the thing can't be handled.

"Type coverage" is pretty useful. Not a huge deal here I agree, but nice nonetheless.