Comment by selkin
I've been doing something similar to the email automation examples in the post for nearly a decade. I have a much simpler statistical model categorize my emails, and for certain categories also draft a templated reply (for example, a "thanks but no thanks" for cold calls).
I can't take credit for the idea: I was inspired by Hilary Mason, who described a similar system 16 (!!) years ago[0].
Where AI improves is by making it more accessible: building my system required me knowing how to write code, how to interact with IMAP servers, a rudimentary understanding of statistical learning, and then I had to spend a weekend coding it, and even more hours spent since on tinkering with it and duck taping it. None of that effort was required to build the example in the post, and this is where AI really makes a difference.