I agree that design is about primitives. wireframes and IA should come across clearly at any fidelity.

But i don't think that's what tailwind and bootstrap are doing. But people very much use these tools to "solve design".

The layouts, widgets, and primitives in these tools are not primitives. I can't deny they get tons of people very far very fast. But my main disagreement is that all of this isn't design and it's not what designers do. You touched on what i agree with: UX flows, diagrams, stories, journeys, personas, etc, these all need to be designed and connected in reality using various primitives for the medium.

Then you slap a cohesive paint job on it, interaction elements, tone and terminology and yes, there is that element of design too.