Those tools existed and they didn't help because users had no recurse against poorly behaving apps. Meanwhile Android kept being reamed by reviewers and media for poor battery life and people kept buying locked-down iPhones instead because they lasted longer.
I spent countless of hours trying to get Android devs to not do dumbass things with battery ("oh, I need updates? I''ll just poll the server every 20 minutes and ruin the users battery in hours. Easier than long polling!") and in the end the situation didn't improve until Google stepped on the devs neck and forced them to use GCM/FCM and started actively powering down radio without apps input.