No, they don't outdo themselves every year. There has not been genuine, overarching atmosphere in years. The event hasn't been connected with a solid story in years. The scare zones have not seen scares in years. HHN 18 was the last year scare zones were genuinely entertaining and, at the same time, creative. Since HHN 15, there has not been cohesion to the event.
Ask ANYONE what were the best houses, and long time vets often will site older houses (Scream House, Body Collectors, Ghost Town, etc.). Yes, there are houses which worked well in recent years, I can't deny that - but those houses had something different about them. It may be the actors waiting even in FRONT of the queue's entrance, it may be the overall event was tied in better, but it was something.
When was the last time we had a genuine icon that wasn't rehashed to death?