> The only thing that matters is that it integrates well and is efficient on the host OS, and that it can sync settings, bookmarks, reading list and stuff between your devices.

In fairness, bar the "integrates well" point, any modern browser will do what you've described (where "efficient" can be used to described a number of different performance related matrix).

>Edge on iOS and Android will have a built-in adblocker soon.

You mean the same AdBlock Plus that allows selected ads to bypass it so long as you paid them?

> The only thing that matters

Well - for some of us it matters that the rendering engine behaviour and performance characteristics are the same.

That's true, and for others it matters that regardless web browser used on iOS, all you need to care for as a developer is that the user is on iOS.

Which are the same as the defaults of the host OS. So there is nothing to make a fuss about.