I've spoken about my dislike of next.js a few times, and it's mostly centered around its documentation. It is decent, but it is no way as complete as an established framework like Django. Have you ever compared the depth of the two? I'm on mobile, just read and compare, I don't know, the routing API docs for both.

Also the APIs are very simplistic, I haven't used it in the past few months when I quit my job, but I vividly recall how anything outside of the simple examples it provides were an exercise in frustration and digging into Github Issues and its source code. The whole data fetching system is so incredibly convoluted if you're doing a little more than static pages or build-time rendering. getInitialProps, getServerSideProps, getStaticProps, hooks, etc., all with their own caveats and performance considerations.

Next might be one of the better JS frameworks but it's laughably bad compared to Django, Rails, Phoenix.