It’s probably because cancp and these other things are buried in fifty or so columns. There’s a column in the groups table for each permission for efficiency.
It doesn’t store the admin permissions though, those are stored elsewhere on a per-user basis, but those are only used for locking down sections of the ACP, and are stored with PHP’s serialize(), if I recall.
cancp is used everywhere outside it, every time an admin check is needed.
And to be fair to whoever made the importer, cancp is a slightly cryptic name. I only know of it because I’ve created custom MyBB plugins before for my own forums (which have since closed down) and I checked cancp to see if someone’s an admin.
cancp basically means can control panel. The Administrator Control Panel, to be accurate.
Moderators have their own more restricted control panel.