I only edit what gets posted here because I don't like looking for caps. I only edit stuff that's HD with clean lines and no noise because replicating artifacts and blurriness to make an edit convincing is a pain in the ass. Someone, or many someones, has a copy of ATLA in 1080p and is doing the work of making caps, so it's obviously getting the most attention edit-wise.
Basically if you want more edits of stuff that isn't ATLA, post good HD caps. Off the top of my head, the new Thundercats, Ben 10 Omniverse or any of the DC/Marvel cartoon movies already have HD caps floating around the internet. If you want something else you'll have to cap it yourself.