Note that you don't even have to std::move a return value in almost all cases. (The very much non-language-lawyer explanation is that local variables are automatically moved from when you return them.)
> return std::move(ret);
it can interfere with return value optimisation (RVO). There might be cases where the move makes sense but to my understanding it's enough to just use return.
It's very much possible to take advantage of modern C++ move semantics without an explicit call to move. Maybe you return a unique_ptr created by make_unique in a factory method, or call swap() on a moveable object, etc. I rarely need to write std::move to take advantage of modern C++ although it took some self-education about rvalues etc to learn how to do it.
But if you have something like a builder object which builds a thing which it keeps as an instance variable; then you have to use `return std::move()` or an out-parameter-and-swap if you want to avoid copies.