I was wondering why jhins final shot works on turrets but caitlyns doesnt.
Also I was wondering why vayne Q doesnt work on turrets.
There's no hard rules with what does and doesn't work, but the common trend is that if a champion has issues taking down a tower, their AA boosters work on towers.
If a champion shreds towers without their abilities: then there abilities can't damage towers.
Champions like Caitlyn and Vayne have no trouble taking down towers due to their builds and kits. Neither do Master Yi or Tryndamere.
Jhin has some issues, especially compared to other marksman.
Pretty much every melee champion that needs to build some level of tankyness to work would also have massive issues if not for their abilities offering some help.