A few weeks ago, I noticed that a lot of Fairies take neutral damage from Steel types due to secondary typing, specifically Tapu Fini and Tapu Koko. Because they're part Electric/Water, types that resist Steel, they end up taking neutral damage from Steel attacks. This is also the case with Magearna, who is part Steel, and because Steel resists itself, it doesn't take super effective damage from Steel attacks.
I also know that Poison isn't the best type in the world, as before Fairy types they were only super-effective against Grass. As of today, there's only one Poison type in OU (Toxapex, which is more or less because of its insane defenses) and 9 in UU. There are 71 Poison types total.
Now, as of Gen 7, is Poison more viable than ever?
All 4 Tapus take super effective damage against Poison attacks (well Tapu Lele is a bit more risky since it's part Psychic but still). In OU (counting UUBL), there are 5 Pokemon that take neutral damage against Steel, being the aforementioned Tapu Koko, Fini and Magearna along with Azumarill and Mega Mawile. There are 9 Fairy types that take super effective damage against Poison in OU and UUBL! That's a lot.
So are Poison Pokemon, or at least Poison moves, more viable in OU then they ever were before?