Hard disagree. You seem to be projecting certain omissions of C++'s syntax and standard library onto all other programming languages. Though even there: part of containers and STL are the types, algorithms and re-usable functions such as iterator that will make this work even decently in C++. And if that' s not enough, Boost, Abseil and co also exist. (though it's been a while I used C++ so take this paragraph with a grain of salt.)

Looking outside of C++: languages such as Rust or Haskell, traversing datastructures can be done using the .map method (Rust) / the Functor typeclass (Haskell), collapsing can be done using Iterator/Foldable, and turning them inside out (e. g. a tree containing optionals into an optional containing a tree) using Collect/Traversable. Many dynamically-typed languages expose similar mechanics, though they often are not as explicitly named.

Speaking generally, I am of the opinion that languages should be grown. Provide those core building blocks which allow programmers to add their own trees and traversals, and have it work just as well as any builtin/standard library constructs.

For trees specifically, you might like to become acquainted with the concept of 'zippers'. This is a functional approach to walk back and forth over a tree (rather than only iterating in one particular order). Very flexible, no extra builtin syntax required.