Lots of things are possible, but possible does not equal probable. It is improbable that the collective brainpower of several police forces (professionals in the field of crime solving with ALL the evidence gathered to date) have all failed to spot what you (a granny who likes to think of herself as a bit of dab hand researcher despite having access to only a year’s worth of evidence and not even all of that) believe exists that points to this being a crime other than abduction. What makes you believe otherwise, apart from arrogance and conceit?
The glaring absence of any tangible, verifiable evidence of abduction? Other than, because the McCanns said that's what happened, so therefore it did. I mean, just look at Rowleys take on the matter. The best he could present by way of abduction evidence was that because Maddie wasn't old enough to leave & start a life on her own, therefore she was abducted.
Maybe I'm wrong though & there really is concrete evidence that the three investigative forces keep closely guarded, & maybe the moon is made of cheese.