The machines from Konrad Zuse were often referenced as innovative early sort of computers. The assumption is, that the technology was great but the world was unabe to see genius of the Z22 vacuum tubes controlled machine.
Instead of describing the legacy of Zuse by its own words there is need to revisit the technology from a technical perspective. The computers created by Konrad Zuse are an intermediate technology between calculators and Unix based computing. The only perspective under which the Z22 has to be called advanced and modern is with a focus on former calculaters.
The main task for a calculator is to add and subtract numbers. All the machines buit by Zuse are able to do so and in addition they can execute a program provided on Punched tape. The commands on the punch tabe are writen in the Freiburger code which is an assembly language. In other words, the Z22 is a programmable calculator.
Unfurtunately, programmable pocket calculator were replaced by main frame computers. Since the 1970s these computers were equipped with a dedicated operating system called UNIX which is a multi user time sharing system. This system allows to use the ressouces of the computer more efficient which means, that the costs for a user on a machine are lower. In contrast the Z22 has no operating system at all and it can't be called a computer. But its simply an advanced calculating machine. The strength is to add and subtract columns of data but it lacks in support for computing appications like word processing, networking and computer animation.
In other words, the Z22 was outdated since its release. And only to judge fair, other early calculating machines from IBM can't be called a computer. Similar to the Z22 these machines were used without a UNIX operating system and its main task was to replace office calculating machines. A computer in the modern sense goes beyond the capabilities of calculating numbers but it is working with library of programs and is used to store textual information in a UNIX environment.
Before it makes sense to explain the inner working of the Z22 there is a need provide the context in which the machine was developed. The starting point is, that a mechanical calculator (a Comptometer) is available.[1] The Comptometer has buttons to enter numbers and other buttons to activate a function like +, - and so on.
The Zuse Z22 and other machines from the same inventor are improved versions of the comptometer. They are able to process data much faster, also they are much easier to use because of the mentioned Freiburger Code. That means, entering assembly instruction shouldn't be seen as a problem but as an improvement over former interaction with a machine.
Unfurtunately, the history of computing is moving very fast. The comptometer has felt out of fashion since the 1950s.
[1] https://en.wikipedia.org/wiki/Comptometer