There were zero dead Hamas leaders on Oct 8, but the ICC did nothing, and did not care. Not to mention there are living Hamas leaders in Qatar, today, and the ICC? Does nothing.
It's a court, not a military force. What do you suppose it should have done, send the special judge forces to Quatar to kidnap them?
The ICC is an institution that requires member nations to adhere to it. Concepts like these require mutual respect for a rule-based world order; an idea that seems to be lost on people like Trump, Putin, or the Quatari.