We write code to solve problems, to be executed by computers, but perhaps more importantly, to be understood by other humans.
Programming paradigms like imperative and declarative programming languages and data structures are abstractions of the real world that help us express the real world in code. We need abstractions because real world problems are difficult and complex, so we model them in programming code with abstractions that help us, humans, put into words (code) what it is that the computer needs to do to solve a problem.
Data structures are another abstraction that help us think about and work with data in the same way. They are a simplification, a categorization of data that helps us group and manipulate data in a way that helps us understand the data we need to be processed, but also to structure the data in way so it can be processed by our code.
Do you need to study and learn things like data structures to be a developer? Maybe not. But having a common set of problem solving tools makes it easier to approach specific types of problems and talk about how to solve these types of problems with other developers when we have a shared understanding and basic set of knowledge that we work with.