How does Imu restrict world's freedom? World doesn't even know this bozo exists.
Celestial Dragons don't know this bozo exists and they still do whatever they wanna still without needing his permission.
Akainu is the one who restricts how people should live:
Akainu is the character that represents that people can't be born free from the sins of their parents:
It's Akainu the one who permanently scarred Luffy, representing that Akainu quite literally left a lasting mark on the MC, not Imu:
Admirals are the reason why people fear the World Government, not Imu: