The Google Gtag extension by Adobe injects the Google Global Site Tag library on the page. It does not provide any additional actions, nor is it required to work with the Acronym Google Site Tag extension. Migrate this extension.
The Google Analytics extension by Adobe uses the Universal Analytics library to send data to Google Analytics. The existing extension does not use the Google Global Site Tag (gtag) library to send data, thus this is not exactly a one-to-one migration. Migrate this extension.
The Adobe-built Google Analytics (Universal Analytics) extension