Like many here, I too blog for the mental exercise of composing, the human desire to express, and a faith that posting to the public web is some how intrinsically worthy. On the first point I've found I get a lot of benefit from the posts I never even publish as I'll keep chewing over subjects which I'm mentally composing a post about and gain a lot of personal clarity in the process.
One thing I've wondered though (and am mentally composing a post about) is whether there's more good in ai digesting ones writing that we might first feel.
Here's a thought experiment: Would you feel good if someone read your blog and learned something from it? Probably yes. Would you feel good if they passed along something they learned to others, likely in their own words? Probably yes. What if they couldn't recall, or didn't choose to reference where they saw it? Probably still yes, although (speaking personally) my ego would probably prefer they did credit. What if the reader who passed the learning along was the ai?
In a sense we're still contributing to the public discourse and culture when we write, just mediated by models. If a model gives someone a slightly different answer in part because of something you wrote, you've still had an impact on the ultimate human reader.
Just to lay my cards on the table I'm no AI booster, nor doomer. In general I think it's over hyped and may well have a net negative effect if steered by those current at the wheel and consumed without due care, but it has its place where it can be useful.