Why didn't Wu in One Piece grab it?

First, Wu must be familiar with this weapon, because he has been using slingshots since childhood.

Second, the gun has a range ~ I saw it in the last few episodes when Luffy and others went to save Robin ~ Wu standing on the tower can hit the navy ~ The navy can't hit Wu with a gun ~

Third, the slingshot weapon doesn't look so good ~ but Wu transformed this humble weapon ~ I believe that the giant slingshot beetle will not be just a big slingshot with a long handle.

Fourthly, the slingshot, a long-range weapon that is fired by personal physical factors such as arm strength and wrist strength, will largely depend on the user himself ~ With the improvement of the user, the weapon performance will naturally improve ~

There are other reasons that I can't think of for the time being.

The most important thing is that eldest brother ODA asked Wu to take the slingshot ~ it was useless for Wu to resist ~