It's easier to destroy than to create. You can knock a house down in an hour. You can ruin a civilization in a couple decades, once you learn how, with an arms race and a nuclear war. As technology advances, governments gain power.
Individuals also gain power.
They can get photocopiers, audio tapes, satellite broadcasts from other countries, air travel, dynamite, automatic weapons, near-unbreakable cryptography, and other dangerous stuff. Nowadays, terrorist groups can blow up airliners in flight and set big bombs in downtown London and New York. In the future, terrorists will be able to do more and more damage. If they do so, governments will have to use more and more of their power to stop them. It may be that even democratic governments will decide to use their full power, greater than it is now, and will crack down on freedom to stop the baddies.