>>45546734It's an early game option to gamble for normal poison. It's not meant to be a main attacking move or competitively viable. Poison Jab is a stronger physical Poison move to inflict normal poison.
>b-but weedle!An early route bug not meant to be taken seriously that you're supposed to evolve for better moves.
>b-but spinirak!That's Game Freak choosing to make Spinirak not have an early attacking move (until Constrict at Lv8 in Gen 2) and rely on the gimmick of getting poison, not a fault of Poison Sting.
>b-but gligar!Encountered at Lv24 in Gen 2 where it already has a different attacking move (Poison Sting, Harden, Sand Attack, Quick Attack, Faint Attack at 28, and Slash at 36)
>b-but roselia!It's the only poison move learned through level up, aside from Toxic in Gen 3.
>b-but cacnea!The only poison move it learns, which is a Lv1 move already forgotten by the time you encounter it at a higher level in the wild.
>b-but skorupi!Lv1 move replacable 3 levels after capturing it in Gen 4. (Would help if someone wants to find one in DPPt and see if it knows Bite, its only other Lv1 move, instead.)
>b-but croagunk!Has other moves to attack with after gambling for poison.
>b-but venipede!Has other moves to attack with and learns Poison Tail at 19.
>b-but frillish!Added in Gen 8 for flavor of jellyfish being poisonous, but learned at Lv4 where you'll never use it as it is found later in the game.
>b-but mareanie!A bulky but weak pokemon meant to do passive damage. Spam Poison Sting until poisoned and then use the all-powerful Peck to whittle away at your opponent's HP.
It's weak, meant to be replaced later in a playthrough, and outclassed when egg moves and TMs are available in player battles, but it still serves a purpose. It gives the player the choice to gamble for poison to provide additional damage instead of just spamming the weak attacking moves learned at lower levels. Still doesn't justify Spinirak having no moves until Lv12 for Gen 7 Leech Life.
