Steel-types are completely out of the question nowadays due to just about 90% of Dragons having either EQ, Fire Blast, or both. And Ice-types are a laughable measure unless you're talking about weavile which iirc doesn't even get usage in OU, I believe. Even then the presence of stealth rock as well as spikes greatly deter ice-types from switching in, the latter holds true for steel types with the exception of foretress and relevant spinners. Even if entry hazards aren't in play, i believe zone is used at least often enough to trap steels as well as kill them. The point being is that the types that originally resisted dragons and beat them are (to some extent) no longer effective at what they do.
Yes, you can make the argument that creating new Pokemon would remedy this issue in theory, but how? In what stat spread would it be necessary to completely wall a dragon? And even then how would you know that these "better equipped" Pokemon wouldn't be countered/checked by some other means before Dragons feel free to spam outrage?
You could make the argument that this is also true against Fairy, that, hypothetically, if Fairy had weaknesses to poison as well as dark, that these things would deter fairies and dragons would feel free to spam all they would like, but the addition of a (hopeful) dragon-resist is a pleasing thought nonetheless. I do hope that the outcome is that Fairies are immune to dragon types, because I don't know about you, but I like switching in my Pokemon while they take 0 damage from an outrage and have a potential to strike back hard.