I 100% agree. I've ran into the same issues, and I would never use Next.js for anything, and I will encourage every team at work to use something else. In general Next.js has so many layers of abstraction that 99.9999% of projects don't need. And the ones that do are probably better off building a bespoke solution from lower level parts. Next.js is easily the worst technology I've ever used.
Many of the abstractions and nextjs tools do things that my OS does better, cleaner and more predictable too. I suppose the overly complicated ENV/.env loading hierarchy is (partly) needed because Windows doesn't (didn't?) have ENV vars. Same for inotify, port detection, thread management: *nix does it well, consistent ish. But when you want an interface or feature that works on both *nix and windows, in the same way…
As long as I can remember in my career, Windows had environment variables. So that's at least 25 years. It's both available to view/edit in the GUI and at the prompt.