Google's Messages app is excellent, and while it does have some flaws, it's no surprise that it's popular. The app has recently crossed the 500 million mark on the Play Store.
What makes this threshold more impressive is that Messages are not part of the Google Mobile Services (GMS) package, which includes apps like Search, Chrome and YouTube. In other words, messages come preinstalled on most Android devices, and manufacturers often replace with their own messaging apps.
Only Google's Pixel line and Android devices come loaded with Messages, so likely this 500 million comes from users going out of their way to download the app themselves
When you factor in the RCS situation, this makes more sense. Some manufacturers, like Samsung, have included support for the RCS format in its texting app, but not all have. Plus, there is no way for third-party SMS apps to hook into RCS. So that leaves messages as the clear choice for those who want RCS support.
For one, it has built-in Assistant features, a dark mode and Quick Replies.
Messages also offers a web interface so users can connect their phone to their computer and send messages from a browser. You can download it from the PlayStation and try it out.
Source: Android Police