Code is written for many purposes, and each purpose requires different constructs which are not interchangeable because of the hardware each is written to run on. There are purposes for client-server, desktop, server-only and mobile, and other more specialised.
Each purpose requires a different code structure, and ultimately all code written for each purpose is very similar, which facilitates the creation of code generation tools and the use of 4GL development environments, per purpose.
The pinnacle of achievement in the building of systems with the elimination of coding is provided by the Remedy ARS [ available from early 90's ], which is applied to client-server. To date, there is no equivalent in the areas of mobile, desktop, server-only or any other coding purpose.
There can be no one method to create all code for all purposes without writing actual code, by virtue of the underlying differences in fundamental functionalities.