Indeed, collation, case-insensitive string matching, and probably a bunch of other things must be used with an appropriate locale. That was the case before Unic

Indeed, collation, case-insensitive string matching, and probably a bunch of other things must be used with an appropriate locale. That was the case before Unicode and is still the case with Unicode. The only difference is that the tables for how to do it are slightly larger now, but the operation itself isn't (much) more complex.