The killer app of WordPress is comments. No SSG, almost by definition, allows comments; WordPress blogs almost always come with them built in. If you want something like Hugo to really take off in the blogging sphere, all you need to do is create some good looking themes with comments . Figure that out at scale - maybe by using per-blog sharded SQLite, which you can host as a third party for pennies on the dollar - a…
Another "interactive" part: contact forms. Not every business site wants comments, but they'll probably want a contact form. Putting an email address out is an alternative, but handling the input pipeline is better. On a static site that requires finding a service they trust to handle the submission and correctly plug it in their site. It becomes another moving part, potentially another bill that needs to be paid sep…
Anything else is overengineering.