Having spent the majority of my time playing TTRPG's in the d20 space, I have always found poisoner archetypes to never really live up to what they should be. Looking at history, reading some Wuxia novels, even playing video games; poison can be a menace. In TTRPG's - especially on the player side of things - I have just always found it underwhelming. Getting poisoned as a played either really sucks or is a minor annoyance, and trying to poison anything - especially at higher levels - lacks the payoff I think it deserves. Granted, this could just be my experience with the games.