In this growing world, security is one of the biggest things that worry lot of users, as lot of bugs are discovered every days than ever before. Though big companies are releasing bug fixes the reach is very less, especially when it comes to Android. The reason is whenever a security bug was discovered by security researchers and Google roll out bug fix, it doesn't reach all the devices, immediately as different Manufacturers like Samsung, Xiaomi uses different kind of Android (it takes nearly a month sometimes, for the manufacturers to release fix). Inorder to tackle the above problem, Google is working on the project codenamed " Project Mainline".
The Main aim of the project mainline is to send updates to every device whenever an issue arises. Google has planned to make this work, through playstore. So, Whenever there is a critical bug fix available, you don't need to wait for your manufacturer to send it through updates, this bug fix will be available for you directly on play store and you need to do is to install that and restart device.
The idea is simple, but it needs lot of things to be done on the background. Again, this is feature is not available for all the devices which is disappointing as Google says, this is currently limited to upcoming Android Q because of the Android fragmentation concept.
We're sure, this will be breaked on One day! but that day is not today 😐