1. There's too many people to have an unbroken, unified front against totalitarian government power.
2. Bell curve natural distribution model stipulates that at least half of the planet is 100 IQ or below, which means intelligent people are naturally surrounded by ineffective retards. Only gets worse the higher IQ goes.
3. Too many useless eaters who still rely on the government to support them, the government is still pretty effective at giving them handouts, and they will fight to protect that government as long as said handouts continue.
4. Government is still too powerful with too many abjectly evil people willing to do anything.
5. Naturally good, altruistic people do not seek power over others. They will continually let themselves be stepped on until the dominator presses their heel in too hard. This, essentially, is the moment we're really waiting for.
6. Evil often undoes itself through its own hubris.