Compared to a normal Realm Fracture, which was like a rapidly expanding hole and could easily be discovered and patched, the Living Realm Fractures were far more problematic.
After all, although they 'absorbed' the capacity of the world much slower, that was only because they were still incubating. If they were given enough time, the trouble they could cause was certainly far greater then the normal Realm Fractures that didn't even have the ability to fight back and revolt.
Once again considering the world a balloon, if normal Realm Fractures were small rips and tears, Living Realm Fractures were like little mites with needles. Before they stabbed out they weren't a threat, but the moment they did, the balloon might just pop in one go, not leaving a single chance for recovery!