Can you be more specific? Which individuals and why (not)?
Note that eg if you're from (picking two random countries) Nepal and commit a crime in Italy, then Italy still has jurisdiction. Italian police can arrest you. [1]
Also, there's certain crimes that any country is allowed to arrest you for, for instance piracy on the high seas.
I'm talking about the sanctioned individuals on the ICC, judges and the prosecutor. The issue is not a matter of certain individuals going to a different country and allegedly committing a crime there. No one is talking about sea piracy.
Note that eg if you're from (picking two random countries) Nepal and commit a crime in Italy, then Italy still has jurisdiction. Italian police can arrest you. [1]
Also, there's certain crimes that any country is allowed to arrest you for, for instance piracy on the high seas.
[1] Also explicitly taken into account in the Rome statue 12(2)(a) https://legal.un.org/icc/statute/99_corr/cstatute.htm