Yet another Goblet of Fire plothole post (Voldemort’s plan makes no sense)

I’ve seen many people online claim that the reason Voldemort used the convoluted plan of kidnapping Harry with the triwizard cup was so that it would look like he died in an accident in the maze, and Dumbledore wouldn’t know that Voldemort was back yet. But Voldemort at this point knew that Snape was working at Hogwarts (Wormtail surely would have told him) and so Dumbledore would know immediately anyway because of Snape’s dark mark. Is there some other reason I’m missing why Crouch/Moody couldn’t just grab Harry’s arm while they’re in Hogsmeade and apparate away, or is it just written that way for the sake of the story but doesn’t really make sense?