Here's what I think happened.
Susperia's Ocampa could eat matter with their mind, which combusted as a by product, which got them high.
Look at Ocampa.
Ocampa is a desert because something removed the nucleogenic particals which are needed for precipitation (look it up in a fake science manual sometime.).
Caretaker took "credit" for that.
If a thousand years ago Ocampan Junkies were burning down their planet chasing the dragon after the Nacene dickered with their biology... That explained a lot.
Why Kes had no idea that she could get high from just doing something as simple as eating matter with her mind and why the Nacene did not move the Ocampa to another planet when if any single Ocampa could have ever again figured out how to trigger their matter eating, they'd kill that world too.
So yes if they were tinkering with the Ocampa to make some changes why not more as to deal with their conception practices?