The basic issue with manual interaction is a question of authority: a pretty common problem for companies (and open source groups) is when $EARLY_EMPLOYEE/$EARLY_CONTRIBUTOR creates and owns the entire publishing process for a key package, and then leaves without performing a proper transfer of responsibility. This essentially locks the company/group out of its own work, and increases support load on community maintained indices to essentially adjudicate rightful ownership of the package name.

(There are a variety of ways to solve this, but the one I like best is automated publishing a la Trusted Publishing with environment mediated manual signoffs. GitHub and other CI/CD providers enable this.)