[tmottabr]

basically every adblock on iphone does this, usually as part of a premium paid upgrade..

iOS unfortunately does not have a way for those apps to hijack the OS level DNS... so they fake a VPN to configure thenselves as the VPN DNS server to allow then to capture all the local DNS traffic..

they do this because it is, as far as i know, their only option to do ad blocking for the whole device instead of just for safari..