How much battery should Android use?

I've always seen people complaining about Android OS and Android System using too much battery. Don't get me wrong, I am one of them. In a %100 battery usage, Android OS + Android System is usually around %25 percent. Whereas the screen is around %40. The rest is app usage and such. I still feel like Android is using too much battery.

And that's the question I would like to ask. In a normal state, how much should the Android OS and the Android System use? %25 seems a lot to me. I mean what could it be doing in the background? If it was after an update or something, I would get it. But it's always like that. I think in my previous phone, which was Jelly Bean, it was way less. Does it start to consume more and more after each update?