Google has recently updated the Play Store to incorporate app quality metrics like resource usage, freezes, and crashes into search results, according to a blog post. Apps that are well-optimized and generally boast a good user experience will be rewarded for their efforts by going higher in the rankings than other apps that may have similar functions but be less perfectly coded, while apps that use up too much processing power, RAM or battery, along with apps that freeze up, crash, or bug out a lot will sink in the rankings. The change rolled out not too long ago, and Google is already noticing a difference in engagement - users tend to keep apps installed and use them often, if they're well-made and offer a good experience.
While user reports are a small factor, the biggest way that Google will determine what apps are doing things right and which ones need to be put down in the rankings a bit in order to preserve a good holistic user experience is a reporting system built into Android. So long as users opt-in when activating their devices, anonymized app usage data such as when an app crashes or how often it causes resource usage spikes will be recorded and sent to Google for evaluation. Thankfully, this same data is available to developers through the Play Console, as well as additional data like what process an app is using when it crashes, what happens before and after freezes, and other details that will be helpful in finding and fixing a problem.
As well as the information piped into the Play Console, Google offers developers a chance to have their app and updates to apps tested on physical devices before the public ever gets a shot at using them. By taking advantage of these tools and paying close attention to user reviews, Google is confident that app developers can improve their situations, and even points to an example wherein an app called Busuu shot up from 4.1 stars to 4.6 stars just by improving app performance and stability. On top of all of that, Google provides a mobile "best practices" resource in the form of the Playbook app, available for free on the Play Store.