That they work for now is only temporary.
There's also the elephant in the room:
1. Those content blockers don't work in webviews and most apps on iOS open urls in web views with no way to choose Safari
2. Apps have no ad blockers either
Gmail on iOS is especially annoying because we often have to open links that require sign-in (e.g. Github) and there's no way to make it open Safari, but it does have an option for opening "Chrome" (also a shell around an iOS webview).
But I love seeing people sticking it to the man :-)