When you've been stuck for 80 years, any improvement at all seems like a big deal. But more importantly, a new idea like this often points the way to variation

When you've been stuck for 80 years, any improvement at all seems like a big deal. But more importantly, a new idea like this often points the way to variations that may also create improvement. Therefore as other researchers pile on, we may see this bound come down further. So yes, it is like a wall in a maze was breached, and there is the opportunity to go further. And it is fair to call that a breakthrough. Of course you're still charging into a maze, and further progress is far from guaranteed.