> But it turned out that those reasons (which you avoid explicating) were not so good for some people after all.
I lived through part of that transition - I'll try and explicate through my own experiences.
The biggest thing automated deployments solved was human error. No more "oops, you forgot to FTP the JPEGs in binary mode" or "accidentally unploaded into a nested www/www folder". The transition was initially to tools like Ansible and Fabric which automated the transfer steps but had to be triggered manually. This also saved me a lot of time and pain.
However, this still left a gap where it was still possible to push broken code into production, so Continuous Integration (and/or Continuous Deployment) became fashionable. The benefits of these were you'd never push code that fails tests to production, the depth and breadth of tests being left up to you.
Incidentally, these developments coincided with my working with ever growing team sizes. There's no way I could have worked with 5 people with everyone S/FTP'ng stuff to prod. Neither would have Fabric + git been sufficient for four 5-engineer team working on the same software product. That's yet another benefit of the new way of doing things: it scales.
I think the additional benefits of checking-in your configuration and deployment steps into a version control system are self-evident.