>>37078484It really depends on which type of poison type you're referring too since it can range from poisonous animal to living pollution. The living trash ones however seem to be integrating poorly. Grimer and muk seem to have an especially rough time going by how the games portray them. Some gen 7 entries mention that they're going extinct since people are cleaning the environment/ there isn't enough bacteria in factory runoff anymore. One of muk's mentions the people actively target them for eradication due to the bacteria they spread. And another one mentions that people have to build sludge ponds as a conservation effort. The alolan forms are an exception of course since they're a form of waste management. Even then though, the alolan forms prey on other trash based poison types like trubbish and garbodor and go berserk when not fed. Trubbish also can accidentally give children life threatening conditions just by burping nearby them according to its dex entry, so they probably don't integrate well.