I don't understand how good content can be automated either.

Recycling content, finding out optimal posting times, posting content ... sure, these can all be automated.

But how do you automate generating content, especially good content and not article spinners or whatever? Can you explain?

Some things you can do in bulk (economies of scale), outsource, schedule, or otherwise automate.

You can create pipelines that save labor - like clients for platforms that make answering common questions / interacting with users way more comfortable and suited to your targeted workflow than the default clients.

On the creativity front, you can also generate random, semi-plausible stuff to inspire you when you're in a rut.

It's not quite about making everything automated, but about leveraging code, systems thinking, and collaborators in such a way that your performance is incredible. It's really feasible.