Why has the idea of power sharing emerged?

Why has the idea of power sharing emerged?

Answer:
The idea of power sharing has emerged in opposition to the notions of undivided political power. For a long time, it was believed that all powers of a government must reside in one person or group of persons located at one place. It was felt that if the power to decide is dispersed, it would not be possible to take quick decisions and to enforce them. But these notions have changed with the emergence of democracy.