Zig aims to be a simple language. It is not easy to define what simple exactly means, but zig is also a low-level programming language that aims for c-compatibility. To reach this goal, it needs good semantics in its type system so that developers have a complete toolbox to manipulate data.
So types in zig are composable, but this can become rapidly overwhelming. See those examples. Are you able to understand them at a glance, as soon as you read them?