.eslintrc.js for React 17 and JSX without import ‘react’

You can read about it in React docs.

If you are using eslint-plugin-react, the react/jsx-uses-react and react/react-in-jsx-scope rules are no longer necessary and can be turned off or removed.

{
  // ...
  "rules": {
    // ...
    "react/jsx-uses-react": "off",
    "react/react-in-jsx-scope": "off"
  }
}

• react-in-jsx-scope on github.

To make it work, you should add those rules to your eslint config, see Extending or replacing the default ESLint config for Create-React-App specifics, every framework should have related section in their docs.