It wasn't the Pirate Alliance that took action, they didn't even know that they had been thoroughly investigated. Some civilizations even had their collective memories altered, captured, and had countless warships and strong persons destroyed without the slightest awareness!
Calling it a technological gap is an understatement.
It's a complete dimensional reduction strike.
"Does the Pirate Alliance really need us?" Some civilizations couldn't help but have such thoughts.
Thus, some wanted to retreat.
This is actually an expression of being frightened. Since humans invited them, there surely is something they need them to do. If it weren't for hiding those advanced warships among them, it might not have been so easy to break the Es Civilization's detection.
However, after perceiving these civilizations' thoughts, Shen Shi simply went along with this change and took advantage of it.
