Because they don't fight for the same slots. The qualifiers are already divided. Why would they count together at the end?
Player Count is a factor but it shouldn't be a major one because a very small amount goes to proplay and historically NA and BR has the best viewership (Outside of China) and results as a region.
EMEA GC is 75-80% europe, and geographically the majority of the scene is smaller US and BR. So there's no reason to be EMEA itself, and not just divide it into EU and MENA (there's not even african orgs qualified lol)
The ideal world would be, of course, expanding GC to 12 teams, and dividing EMEA into EU and MENA. But sadly they're not doing that, so there's no reason to give 3 slots to EMEA
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