Kinda defeats the purpose of NextJS's organization - the filesystem based routing is pretty key to their server side rendering logic and the cornerstone of their sensible defaults for making performant applications out of the box, vs just having a wildcard route that runs React Router - might as well just use CRA in that case, no?
Why would anyone use CRA when there is next? Either I write my webpack config, or I use a comercial tool with sensible default, and the flexibility to mix and match single page and SSR in the future.