From what I can tell, !coolguides has a fairly rigid set of rules, with a specific distinction made between guides and infographics. That’s great, I like when moderators take an active role in curating the content of their communities.
But I would guess that !coolguides is possibly a response to those rules. Basically if your post got removed from the lemmy.ca community because it was technically an infographic, you could post it to sopuli.xyz community instead.
That’s my understanding of the ecosystem, without having spoken to any of the people involved.