You never need to use everything a language provides. You find the parts useful to you or your team and use all of them. I was a C++ developer for a decade an

You never need to use everything a language provides. You find the parts useful to you or your team and use all of them. I was a C++ developer for a decade and knew a fair amount of the C++13 spec but never needed to use even half of it in production. I've been a Java developer for years and don't know 10% of the standard library there. That doesn't make either language poorly designed by itself.