Hardly. I beg to differ on all counts.
Your first sentence is self-contradictory, as that particular use of strikeout has only appeared in the digital era. In fact, the opposite is true: it is now filtering down into print.
Ok, so yes, I’m trying to
sell make the case for this feature’s inclusion. But I fully stand by that statement: particularly, on the internet, where the lack of tone and inflection often makes it difficult to convey the writer’s intent, strikethrough stands apart in its power a metadiscursive device that can variously be used for apophasis, epanorthosis, implied criticism, wry humor, irony, etc.
Of course, additionally:
It is often used to render completed items in a list.
And, more critically, it is frequently used to preserve the “revision history” (illustrate where and how text has been changed) in revised blog posts, etc., which have been updated since their first publication.
<s> isn’t particularly onerous. But the spec (as it reads today) does allude to the possibility of non-html rendering targets, and these would benefit from the inclusion of this extension in the standard, a feature which is already implemented in a good many Markdown implementations.
I measure it all the time!
And, if “strikeout is just trying to make digital text mimic pen and paper”, ok, but isn’t Markdown “just” trying to make HTML formatting mimic plaintext email?