HariSankarD Ideally, the OS should handle the threshold for terminating background apps by being less aggressive (even on 8gb models) rather than relying on the user to manually unrestrict battery usage for apps, which can impact battery life when those apps are not running in the background. I believe there is a scope of improvement in this aspect.
In this regard arter97 has done some great work for Phone (2) which is worth mentioning. Am linking his tweet as well for reference.