See my comment on TAForObvReasons - If you invest in a Safari Content Clocker that allows custom rules, you can effectively do the same thing as a hosts file. Safari Content Blockers prevent network traffic similar to host files works. The only thing you wont be able to block is some app that has a Facebook analytics or Facebook login dependency inside e.g.
Spotify.
On my jailbroken iphone(s) one of my first steps of security hardening is to replace the hosts file.