As I recall (I received First Communion in 1953), distributing Communion went a lot faster when we still knelt at the Communion rail and received on the tongue. The priest moved along the rail, almost like an assembly line. Standing to receive slowed things down enormously -- you have to wait for the person in front of you to move out of the way, then step up, then step away so the person behind you can step up.
In our parish we have 4 ministers distributing the host and 4 distributing the chalice...quite efficient and rapid.