First, you seem to be addressing the weakest form of their argument, not the strongest. It's reasonable to understand that some disciplines become obsolete or outdated.
Second, you framed your point as a rhetorical question with an obvious answer. At best, it waste people's time on a low latency communication platform, at worst, it is condescending and a common from of trolling.
In my experience, effective communication means addressing the strongest interpretation of what they're saying, and cutting to the chase by bringing your strongest most relevant points.
