What if the AI produces writing that better accomplishes my goal than writing it myself? Why do you feel differently about these two acts?

For what it's worth, the unifying idea behind both is basically a "hazing ritual", or more neutrally phrased, skin in the game. It takes time and energy to look at things people produce. You should spend time and energy making sure I'm not looking at a pile of shit. Doesn't matter if it's a website or prose.

Obviously some people don't. And that's why the signal to noise ratio is becoming shit very quickly.

It doesn't, is the problem. If it did, I would feel differently.