In the US it’s woefully abused, though - political cronies are excused their crimes as a quid pro quo in return for silence - it’s appallingly corrupt and unprincipled.

People who are guilty of a crime and prosecuted fairly under the law should generally serve their sentence. Exceptions to that are best managed by an independent and transparent tribunal who can give principled reasons for commuting specific sentences, for example a prisoner serving a very long term has undergone a genuine moral transformation and is now safe to release, or changes in society have rendered prosecutions of a certain time and place anachronistic and unjust be modern standards.