I'm trying to use Webpack and babel to create an ES5 compatible output of my typescript code. The resulting bundle.js file however still includes ES6 keywords such as let. How do I go about making the output truly ES5 compliant?

Below is my webpack config file:

const path = require('path');

module.exports = {
  mode: "production",
  entry: './src/intersight.ts',
  module: {
    rules: [
      {
        test: /\.tsx?$/,
        use: [
          {
            loader: 'babel-loader',
            options: {
              presets: [
                ['@babel/preset-typescript'],
                ['@babel/preset-env', {
                  targets: "defaults",
                  forceAllTransforms: true
                }]
              ],
            }
          },
        ],
        exclude: /node_modules/,
      },
    ],
  },
  resolve: {
    extensions: ['.tsx', '.ts', '.js'],
    modules: [
      path.resolve('./node_modules')
    ],
    fallback: {
      crypto: require.resolve('crypto-browserify'),
      http: require.resolve('stream-http'),
      https: require.resolve('https-browserify'),
      stream: require.resolve('stream-browserify'),
      url: require.resolve('url'),
    }
  },
  output: {
    filename: 'bundle.js',
    path: path.resolve(__dirname, 'dist'),
    libraryTarget: 'umd',
    globalObject: 'this'
  },
};