The recommended ESLint rules catch most of the bad stuff, and these days this is all you need in your ESLint config to enable them:

import {defineConfig} from 'eslint/config';
import js from '@eslint/js' 

export default defineConfig([
  js.configs.recommended,
]; 

There's one use case where == is still commonly used: == null matches both null and undefined. Lint rules that block == usually allows the null case as an exception.