What is "Pluto" and why don't we have access to it?

[Belhi]

Stepping foot inside Azys Lla/Lost City of Amdapor/Aurum Vale...etc. and probably battling half the stuff in this game could have long term health consequences too. So what?

Yes but we generally actively try to mitigate the risk. Of course it could quite possibly also be considered contraband and have other effects like effects on behaviour and judgement.

There is plenty of reasons a drug we have only seen used by criminals wouldn't be something we take.