Show HN: Self-Host Next.js in Production

I haven't really followed Next.js and the related ecosystem closely, what does this project do exactly? If I look at Next.js docs [0], they have three options for self-hosting: using a Node server, using a Docker container or as an SPA. Is this project a wrapper around one of those or is it something else entirely? Or to perhaps ask differently, to me it seems you can already self-host Next.js, what's the value add of this specific project?

[0] https://nextjs.org/docs/pages/building-your-application/depl...