If one other human sees value in it, it has been worth the extra trouble. When I advertised my blog on my HN profile, people came to read, some even wrote to me.
So what if 99.99% of Internet users won’t find it any more because they use LLMs? Then write for the 0.01%. Those are the people I want to engage with anyway.
Publishing changes the incentive of how you write, because you’ll care differently about the quality and content of the writing, since people might read it. That’s valuable for a writer.
The same reason you might scream out loud to no one in particular instead of just thinking it in your head.