A while ago I stumbled upon tips for my Samsung Galaxy S7E and I found a very useful one. The app Adhell, is an adblocker that is system wide without the use of a VPN as it utilises KNOX (no root needed and I assume you need to be on stock firmware).
https://play.google.com/store/apps/details?id=com.getadhell.…
This app does not affect battery life whatsoever.
I thought I'd share this useful tip for those that weren't aware of this app.
Nice