Can I update/assemble new ionic.bundle.js from ionic1 to ionic2/3?

Is there some best way to update ionic.bundle.js from ionic1 to ionic2/3 or assemble new?
I understand that ionic2/3 have another flow and file structure, using webpack to assemble and serve the projects.
But we have legacy project with cordova and ionic 1.3.1, which is not installed and loading like ionic.bundle.js thru requirejs.config.
So usual upgrade tutorial is not exactly what we need.

Thank u in advance!

    baseUrl: '',
    waitSeconds: 0,

    paths: {
      'ionic': './lib/ionic/js/ionic.bundle',
      'app': './js/app',
      'routes': './js/routes',
      'controllers': './js/views/controllers',
      'components': './js/components/components',
      'services': './js/services/services',
      'filters': './js/filters/filters',
      'scripts': './js/index'

    shim: {
        exports: 'angular'
      'app': ['ionic','controllers','components','services'],
      'routes': ['ionic'],
      'controllers': ['ionic'],
      'components': ['ionic'],
      'services': ['ionic'],
      'filters': ['ionic'],
      'scripts': ['app']

    deps: ['./js/appStart']

I think you have to create new project and start it from zero because as you know between ionic 1 and ionic 2,3, & 4 in much different. It looks like you have design and code it won’t take much time in upgrade.

I understand that the official way is to start a new Ionic 2 app from scratch like described here but I thought maybe someone had more painless way experience with ionic.bundle.js than creating totally from scratch.

For example just loading new ionic.bundle and converting Ionic 1 view/controller to an Ionic 2, Angular directive usage, like ng-repeat and ng-if to *ngFor, *ngIf.