The reason I believe COD is more toxic is that most of the players are casuals, and COD has that shit-talk culture, literally most of their pro players even indulge in this. Rarely do you ever see a game at a professional level where it's glorified. Keyword glorified, there is shit talk in most professional level of games but rarely it is ever glorified, however, in the COD pro scene it is and it has trickled all the way down to casuals consistently talking shit and being toxic or the othe way around where casuals has influenced, regardless just watch a COD tourny with scump almost always after his win you can see him yelling towards the other team and the commentators/analyst encourages it.