They have jurisdiction over Palestine, that’s why they issued the arrests at all.
The point is diplomatic, politicians and other influential people in countries all over the world will find it easier to argue against Israeli interests. This is actually a major blow to Israeli diplomacy.
Well, this happened for example.
https://www.npr.org/2023/07/19/1188568761/russia-putin-south-africa-brics-summit
This is a diplomatic blow to Israel, and if it ever becomes as isolated as Russia is from Western commerce, it will cease to exist.