By this reasoning, a pen and paper aren’t UX design tools either.
Shane Goodwin

By and large, tools are not general purpose. If you need to cut down pine trees, a hammer or a Swiss Army knife are not very useful.

My argument is that we need tools that can better support UX design processes and provide useful models for the implementation phase.

I’m not convinced Sketch can provide the basis for that because the underlying model doesn’t have enough semantics. Bolting on plugins can only take it so far.