It was considered a menial position wasted on Lenin himself, Trotsky, or Zinoviev
It's not completely accurate to say that the General Secretary was created in 1922. The position evolved out of Technical Secretary of the Central Committee, which then became the Chairman of the Secretariat as the administrative needs of the Bolsheviks evolved. Then it became Responsible Secretary, and finally General Secretary.
At its creation, the post was a purely administrative one, like the Secretaries before it. Lenin even referred to Stalin as "comrade card-index." However, one of the things it controlled was the membership of the Communist Party. Stalin took advantage of this as a way to build up a power base in the Party and reduce the influence of his enemies.
The General Secretary post became influential because Stalin was influential, not the other way around. Originally, the Chairman of the People's Commissars (Lenin's position) was the leader of the nation.