Observation: I absolutely wouldn't build a long term project using Nextjs without having full time development resource able to perpetually support the project.
Why? The API surface changes way too much and often.
A project like JS Bin, 16 years old, would have required constant support ALL of the time to keep it running.
Instead, it used express, which is a relatively "basic" pattern, but the complexity hasn't changed.
I enjoy Next for quick and dirty, but decade+… I don't think so.