Its selling point seems to be that it's "simple". Although for me Wordpress for instance is simple too in that it can be up and running within 10 minutes.
It's hard to tell from the initial docs, but I think this generates pages statically, so unlike Wordpress, you're not relying on a DB to serve content.
If that's true, it seems like the kinda missing bridge/glue between generators like Jekyll/Hugo; allowing static content without needing to be a web dev.
But seriously, in my experience, I'd rather use something other than Wordpress. There are lots of things it does well, but not usually for the projects I work on. Use the tool that works well for the project.
Made many, many WP sites over the years for clients or otherwise. It's brilliant for what it is. You can do SO much with it. Stuff like this always intrigues me though - I'd happily replace WP for client sites where they may want to make some minor amends to copy / content (and thus I can sell "you can edit it yourself" as part of the package), but they don't have to worry about updating it and all the heaviness that WP brings.
The thing I always kind of thought was crappy is that because WP has so many plugins available, it becomes difficult to build even simple sites on a different platform if there is even a small chance you may need more functionality in the future.
My go to example is a simple payment order form (or sometimes forms in general depending on the CMS/static site generator).
If I use this tool, there are no forms. Client comes back a year from now and says they want to add a form. So after much fuss we move to something with forms. Then another year later, they want to take payments for $20 T shirts. We could spin up a 3rd party service but sometimes that makes things even more complicated.
If I started on WP, I can use one of the dozen form builders that support basic payments and I would have saved my client thousands of dollars of transfer fees and hours of my own time converting data between these platforms for little gain.
I say all this as someone who builds mostly WordPress sites at this time, though I’m always trying out new things too.