Being neuro-atypical, I understand the desire to be "technically correct, the best kind of correct". It would be so much better if we used each word for their exact meaning.

But that's not how most human communication work. When people say "I cannot come tomorrow", they usually don't mean they can't. If you gave them one billion dollars to come, chances are they would.

This is a fairly common convention, and most people in the English language are using this approximation and assumption.

You can chose to ignore it of course.

I consider I've done my part in this conversation, and wish you a nice day.