No, launching an app on playstore doesn't in anyway guarantee or showcase a successful platform, there is more to take into consideration. There are many projects with good apps on playstore, but are no where to be found owing to the lack of the right expertise to keep the platform valauble while making the app more relevant each day. On the other hand, there are projects with their app on playstore and still doing well because the team keeps looking for ways to update the platform as well as the app. Let's take Binance as an example, their app is on playstore and is constantly updated while the team keeps looking for ways to maintain the platform through various Implementation of features, services etc.