Why the File .npmcheckrc?

Packages that seem to be unused are mentioned in this file so that they are ignored when running npm-check on the command line.

@fontsource/roboto and @types/react-dom

These packages are required for MUI.

@types/node

This is for TypeScript intellisense in a node environment.

babel-jest and jest-environment-jsdom

These are required for using Jest with Next.

identity-obj-proxy

The reason is unknown. Perhaps it is something to do with ESLint?

husky

This package is used for a pre-commit hook and a pre-push hook.