You could say it's similar, but only insofar as WordPress+Timber is also similar (i.e. coding a custom site for end users to easily edit content).
I'm not sure I understand your second question, but I believe lots of those already exist, and it made more sense for my use-case to just build the site directly from primo.
Well, primo is an SSG, but some advantages over other SSGs: no setup for Tailwind/PostCSS, no setup for js modules/libraries, reusable components, coding from the browser, encapsulated component styles, developing components in isolation, wiring up components to fields in seconds, and a CMS your mom can use. More to come by version 1.
If I understood it correctly, the devs create the components and the end user (editorial people) can edit the content in a nice editor. Like this: https://imgur.com/7W9zcW9
I'm not sure I understand your second question, but I believe lots of those already exist, and it made more sense for my use-case to just build the site directly from primo.