AdAway is main reason, why I root android devices. It block ads in all apps and browsers even on data, without VPN.
Another way how to block ads on data is using OpenVPN to connect data through you home router that has ad-blocking. But it is limited by upload speed of home network connection and battery drain of your smartphone is worse with active OpenVPN.
I use OpenVPN/Wireguard to setup split-tunnel VPN, only route DNS traffic to Pi-hole at home network. Although my connection may be leaked, I thought it's faster since 5G is faster than my home network upload speed.
But your speed in device connected to OpenVPN/Wireguard is limited by upload speed of you home connection. Not by data connection speed on client device.
Yeah, So I use split-tunnel. For example only route 192.168.1.0/24 via VPN, then set 192.168.1.10 as DNS server. Therefore I can use pi-hole at home and other traffic are routed by 5G directly.
Another way how to block ads on data is using OpenVPN to connect data through you home router that has ad-blocking. But it is limited by upload speed of home network connection and battery drain of your smartphone is worse with active OpenVPN.