https://techcrunch.com/2019/05/08/google-play-is-changing-how-app-ratings-work/

Two years ago, Apple changed the way its app store ratings worked by allowing developers to decide whether or not their ratings would be reset with their latest app update — a feature that Apple suggests should be used sparingly. Today, Google announced it’s making a change to how its Play Store app ratings work, too. But instead of giving developers the choice of when ratings will reset, it will begin to weight app ratings to favor those from more recent releases.

“You told us you wanted a rating based on what your app is today, not what it was years ago, and we agree,” said Milena Nikolic, an Engineering Director leading Google Play Console, who detailed the changes at the Google I/O Developer conference today.