Yup, they're different. No different content though just two communities set up for the exact same thing. I don't think it's a great idea personally as neither seem too active compared to both combined but it's what the community wants.
There's a few more than that too, but these are the most active
Considering it has more (and likely more active) moderators, I'd personally strongly advocate migration over to [email protected]. The reason I made this one was because I'm even more passionate about this editor than anything I edit with it and had just grown impatient at no one prepping up a community for it. There's value in being a member of both if one instance suffers outage, but I agree posting in more than one place hurts the community. Maybe I should make a pinned post about it, asking for input.
Yeah. I feel the same. Although the idea of federation and ActivityPub protocal is very nice, I think it'll be better for a single community, either official or a comunity cooperated one.