Why use webpack when developing(not production)?

[nswon]

Summary

reference: I'm a webpack beginner.

package.json

"scripts": {
    "start": "electronmon -r ts-node/register .",
  },

this is a simple way to run an electron.

However, the boilerplate runs as the webpack dev server.
When developing, I think it's good to run it as a client-side rendering without using a webpack.

main.ts (main process)

mainWindow.loadURL('http://localhost:3000');

and It's right to bundle in webpack when deploy!
Is there a reason to run it with webpack when developing? Is it faster?

thankyou