I didn't mention run-time dynamic dispatch, only a function dictionary (which C++ calls a vtable). Using traits for bounded subtype polymorphism is much like having a dictionary of functions that can be resolved completely at compile time, making it possible to use monomorphization and static dispatch.

Not if the standardised way is worse than the naive way, like in C++. Then I will rather take manual virtual calls, like in C: https://elixir.bootlin.com/linux/latest/source/include/linux...

It isn't that much more work and it's not something you end up doing terribly often. I think destructors are a much more important to help day to day development and avoid bugs.