If you programming language has this concepts and even then this will highly depend on the programming language you are using. The right data structure does no

If you programming language has this concepts and even then this will highly depend on the programming language you are using. The right data structure does not only depend on performance. I can write you the most performant code in the world if you want to but it will take 5 years. Oh we only have 1 month? then sorry for now an Array will do. In most cases you pay someone for the skill to learn new things fast and stay motivated. Why? Because in good companies you want to hold on to the people for a long time and this people need to educate themselves. Why? Because even the basics depend on the context they are in and languages, frameworks and runtime and other stuff will change over time. 20 Years ago memory space was a problem? Do we even think about memory now? Not really unless your working on some embedded systems.