They just did a demo with a simple form and looking at it seemed so obvious.
There was no useState per form element, form data was trivially validated on the server, errors were trivially sent down to the server. If you look at this example[0] you'll see there's not a single useState, useEffect, etc.
Fundamentally, Remix is about using native browser behavior to build websites. The imported `Form` component is replaceable with the HTML `form` element and it all still works.
I think Remix is going to be even better than NextJS. This isn't a rivalry though, just an alternative solution. Clearly NextJS and React frameworks broadly are valuable, Remix is now another option.
I really like that Remix's architecture means you end up writing code that would execute on your server and not the client. It feels like a much nicer balance rather than doing everything on the client.
[0] https://github.com/remix-run/remix/blob/a56bdfd7f7e7fa9d8a3b...