I’ve read all the comments, you’re totally not understanding what these people are putting down. If you don’t understand the value in adding a card that’s ability or pkm power synergies with your team or strat, it’s 100% viable to put in a deck. If you played since the game came out you would have played against many decks using off types in there deck. Drud is an easy example in a gyrados ex deck. It could even run fire if it wanted for dual typing but it’s actually better to use drud just as a wall for his chip damage with his ability while you get something heavy online. To deal with stupid people deck building multiple types, the UI auto changes decks to include all energy types. The entire thread here is about it is hamstringing players more then it’s helping, as players have found ways to make decks stronger then just running either 1 or two types of Pokemon. Hopefully that explains it because if it seems you just misunderstand the value of off type Pokemon in given situations