It might seem like losing a planet in the milky way galaxy was the same as losing a drop of water from an ocean but in reality?
Those planets were extremely vital for the survival of the galaxy!
That's because the moment a void portal appeared in the matter universe, the void creatures do not spread and start searching randomly for planets or lifeforms.
Instead, all of them target the closest planet to the portal like they had a GPS implanted in their minds.
It didn't matter if the distance was merely a couple of hundreds of thousands of kilometers or light-years, they always spot said planet and invade it!
Naturally, everything on their path gets hunted down as well!
This entailed that with each falling planet, the void creatures would gain more ground inside the galaxy and continue targeting the closest planets to them.