C++ is still missing optional Reflection/Introspection. With that feature it could easily replace majority of todays typed languages (with exception of language such has Haskell or Rust).
Reason is that reflextion allows to close a 'external data types' dissonance that currently is present in C++. In other words it is not possible to develop 'framework software' that can introspect plugin/consumer code to derive how they view the externally defined data sources (eg Databases, UI kits, JSON streams/etc).