In one word, Vanced MicroG is a Vanced add-on app which developed by Team Vanced which allow users to sing on YouTube with your Google Account. Not only Google account, this app also help you to sign with your HUAWEI account if you have this brand device. If you think why you have to use this app to sing in your Google account, then let me tell you YouTube Vanced or Vanced Music app dose’t support direct sign in, because this is a modded version which gives features like premium. So this is the way the developers gives you to use your YouTube Vanced with Google account. The good news is if you want to use YouTube Vanced app as a guest, then you don’t need to sign in Vanced MicroG app with your Google account.