Webpack is slow at "95% emitting CopyPlugin" during hot reload with VueJS

During hot reload, Webpack gets stuck at 95% emitting CopyPlugin for a few seconds.

I have many files in my public folder, mostly images (about 1GB), which must be displayed on my VueJS app. If I remove them, I no longer have the problem.

Here are my package.json dependencies:

{ 
  ...
  "scripts": {
    "serve": "vue-cli-service serve",
    "build": "vue-cli-service build",
    "lint": "vue-cli-service lint"
  },
  "dependencies": {
    "core-js": "^3.6.4",
    "register-service-worker": "^1.7.1",
    "vue": "^2.6.11",
    "vue-router": "^3.1.6"
  },
  "devDependencies": {
    "@vue/cli-plugin-babel": "~4.3.0",
    "@vue/cli-plugin-eslint": "~4.3.0",
    "@vue/cli-plugin-pwa": "~4.3.0",
    "@vue/cli-plugin-router": "~4.3.0",
    "@vue/cli-service": "~4.3.0",
    "babel-eslint": "^10.1.0",
    "eslint": "^6.7.2",
    "eslint-plugin-vue": "^6.2.2",
    "sass": "^1.26.3",
    "sass-loader": "^8.0.2",
    "vue-template-compiler": "^2.6.11"
  }
}

And this is my vue.config.js file:

const path = require("path");

function resolveSrc(_path) {
  return path.join(__dirname, _path);
}
// vue.config.js
module.exports = {
  lintOnSave: true,
  configureWebpack: {
    // Set up all the aliases we use in our app.
    resolve: {
      alias: {
        assets: resolveSrc("src/assets"),
      },
    },
    output: {
      chunkFilename: "[id].[hash].js",
      crossOriginLoading: "anonymous",
      filename: "[name].[hash].js",
      path: path.resolve(__dirname, "dist"),
    }
  },

  css: {
    // Enable CSS source maps.
    sourceMap: process.env.NODE_ENV !== "production",
  },
};

I would have expected Webpack to cache my public files, and not copy them again at each reload. Maybe there's a way to configure it, but I don't have a good knowledge of Webpack and vue-cli. If anyone has a solution to cache/speed up the hot reload of my app, it would be great, many thanks!