The court is the highest UN body for hearing disputes between states. Its rulings are final and binding but have been ignored in the past, reports Reuters. The court has no enforcement powers.
Was it? Look at Germany or the rest of the EU for example. It would make it much easier to argue for divestments and sanctions in parliaments if there was an active warrant against Bibi.
Yeah, it's definitely not going to be enforced but it's still breaking the Genocide Convention. It basically says that in the future Israel might not comply with international treaties if it doesn't feel like it. This makes them hard to work with as a country.
Then there is also bilateral actions such as sanctions as a tool to put pressure.