>>36301993Defeatist (Archen), Truant (Slaking) and Slow Start (Regigigas) all fall in the category of trying to nerf a Pokemon that might be too powerful on its own, but only succeed in completely crippling the Pokemon. In Pokemon GO, Slaking isn't hindered by its ability because there aren't any, and it's the go-to Pokemon for gym defense, along with Blissey.
There's this niche tactic of bringing these Pokemon in BECAUSE of their bad ability, and then forcing it onto the opponent through several Skill Swaps. I've seen it done at least once with Delcatty's Normalize, where the rest of the team was Ghost types, essentially making them immune to every attack.