One of the greatest innovations for terminal design would be to place security, instead of being at the first opportunity as soon as you pass check-in, to have it at the latest opportunity, at the gate immediately prior to boarding the aircraft.
There are a few airports (principally in Asia) who do this. It is amazing the benefits given (you may care to start a list; it will be lengthy).
The quantity of security staff and equipment required is NOT grossly increased, their productivity per shift appears broadly similar to the current approach. Those who claim it is inefficient have not thought it through. It's a question of organisation.