>>32101114It made Landorus-T even better.
In all seriousness, people are still discovering uses for it.
One of the first discoveries was Z-Conversion Porygon-Z. That thing is great now.
Moxie Pokémon, like Salamence, Gyarados and Krookodile also like them. Z-Fly for Salamence and Z-Bounce for Gyarados.
Speaking of Z-Fly, Landorus-T got a lot more threatening. Z-Fly destroys bulky grass types (like Tangrowth and Venusaur) who walled Landorus before. Z-Stone Edge destroys flying types that walled it before. Hence, Flying types and Grass types are no longer safe switch-in's for a set-up Landorus.
Z-Solarbeam does similar things for some grass types. Heatran and Volcanion like having it.
Recently, Gengar (who is now UU) is seeing a resurgence in OU due to its Z-Shadow Ball, which very few Pokémon resist and can then 2HKO most bulky walls (bar Chansey).
But the claim in the prerelease days that Z-Moves would make shitmon competitively relevant never happened. As I said, it just make already great Pokémon better.