What did you move to? We've been using NextJS as a frontend with somehelpful server-side/api handling, but the backend is done in Django. We are basically just using ReactJS with the convenience of NextJS (like file based routing)
Not OP; but when I was thinking about using Next.JS, and doing a deep investigation, I came to the decision that, for server-side rendering, I'm quite happy to use Kotlin and Ktor (my backend is also Kotlin - I have a lot of client-types, which is why they're separate), and I've been quite happy with Ktor's html dsl + htmx for speed.
And Kotlin + Ktor feels very good to write in on serverside. Fast, easy and fluent to write in, like Ruby; but with Java's ecosystem, speed and types.
We have some other projects that are Angular, and NextJS was sort of a proof of concept for us. The goal is to just have one front-end framework for our devs to work with (and keep up to date, ugh!), so we’re folding those deploys back into our Angular family of features.