I'm trying to migrate from Google analytics to the new Firebase analytics but I noticed there are libraries for ads too. Are firebase ads going to replace admob ads as well? Should I keep using admob via google play services? Or make a switch to the Firebase SDK? What's the difference anyways?
Happily, these are the same thing! The 'firebase-ads' dependency just brings in the existing 'play-services-ads' library and the 'firebase-analytics' library. The Firebase SDK is part of Google Play services, so no need to worry about migrating, just update to the latest version.
Exactly as Kastriot says, the main integration is between Firebase Analytics and AdMob, but the AdMob SDK is still the same service you're already familiar with.