Yes, you can write some storage solution or yet another database without knowing ACID terms but you will still end up somewhere in the CAP triangle. Using common terms like these makes it easier to communicate with other engineers and makes it more obvious that a lot of things have already been solved and perhaps there’s a library that you can use. In the same spirit you should not write your own cryptographic algorithm and for example you could develop an API that is not RESTful but it’s more interoperable when you are using standards and prior knowledge. I personally would not hire a guy to work databases if he insists on not having to learn about ACID.