Yeah, but honestly I don‘t think it ruins the game. Sure, it’s not the best idea, but I don‘t care too much. I actually care more about the fact that the gameplay currently sucks and is completely different to Overwatch 1. 5v5 and the overall balancing sucks.
Safari on iOS supports extensions out of the box. You can just install adguard or something else and won‘t have any ads.
There are also third party browsers, which yes, use WebKit, but also can block ads.