It’s a language issue. NA (Canada + US) has almost 100% English understanding among the ppl on twitch and it has a lot of people who want to watch streamers. Thus NA streamers have a big fanbase of interested people who can understand them.
On the other hand EU streamers can only appeal to the fraction of their interested parties. If Nats speaks Russian on stream, he’ll be unable to tap into the viewership of all the non-Russian speaking viewers. If he speaks English, he can’t get all the Russian people who might want to watch but don’t know English. Same goes for people from any other country. This same logic is applies to why EU ranked can be so difficult as well. More languages divide the population, so communication is harder, which means misunderstandings that cause frustration, and thus more toxicity from said frustration.
Apac overcomes this language barrier a bit by having large interested populations in specific regions (like Japan or Korea). That’s why certain Japanese streamers speaking their native language can get such a large viewership for Valorant.
It’s really an interesting phenomenon but definitely not the consequence of EU streamers falsely being stated as less personable.