Perhaps it is something in the nature of these other realities that bring others to them, to favor 'humans' as a species. Something that may make them more accessible.

[ She murmurs, idly working a hand into Lup's hair. Humans in general were an odd topic for her, so she was mostly intending to keep quiet, but... it was an curious thing. ]

Some seem to not be aware of the existence of other species, let alone have the ability to travel to other worlds within their own universe.