Germany has a very sad and weak airport security story. The security personal are hired and paid by the state (Land), and thus the state plans their capacity and workflow. The airport owner (i.e. FRAport) has no say in their internal work organization, as it is basically contracted out policework. For whatever reason, most german Airports I regularly use, use the same machine and broken workflow: There is only a limited amount of containers to put your stuff in to go through the x-ray, and the machine itself has an integrated container-return system using conveyors. As a result, each machine has only a single small table with a container dispenser to serve passengers. On that tiny table, only 2-3 people at the same time can get undressed, get water out of their handlugagge etc. Waiting passengers behind them are blocked.
I contrast that with my experience in Spain: Several meters before the machines, there is a large amount of unoccupied, huge tables with containers stacked everywhere, so everybody can get undressed and pack their stuff into the container trays at their pace of choice. Staff assists and tells the rules to individuall travellers. Once you are done sorting your stuff into the containers, taking off your belt etc - only THEN you take the containers towards the x-ray conveyor line. So there is hardly any blocking the line. Instead of a container-return system, a single human stacks the containers past the scan and returns them to the beginning. This is so much more effective.
Classic example of government run workflows: No one cares to optimize the workflow, and the one who would benefit from a speedup (the airport and the airlines) in terms of increased sales, have no say in the process.