The JSON API is already overloaded for QString/QStringView/QLatin1String, so it's the perfect candidate for replacing all of these overload sets with a single QAnyStringView function.

Additionally, the toString() functions could get companion toStringView() functions that return views into the internal string storage (which may be US-ASCII, UTF-8, or UTF-16, so needs QAnyStringView). (→ QTBUG-133688)