As Karl Popper taught us, there's more than one way to approach the truth.
This doesn't prevent topics from having prerequisites (you need to learn X before Z – Z builds on X). It sometimes gives you options about prerequisites (you could use X or Y as a prerequisite for Z, there are two known approaches to Z, one using X and one using Y.)
Prerequisites relate to different ways to organize knowledge. There are options for that but for many issues only a small number of known options are good, effective and efficient. One day we might learn some new, good approaches to a topic. At that point you could perhaps use W as a prerequisite for Z instead of X or Y. But today people don't know about that option.
Look at currently existing approaches to a topic, look at their prerequisites, choose one of the approaches, and learn the prerequisites for it. Don't try to skip prerequisites on the basis that there's more than one valid approach to a topic.
What some people do is basically say "There is an approach where X isn't needed, so I won't learn X, and there is also an approach where Y isn't needed, so I won't learn Y." You need to pick some particular approach, see what knowledge is needed for it, and get the knowledge.
People often refuse on the basis that some alleged prerequisites are unnecessary. That people sometimes make mistakes in identifying prerequisites doesn't invalidate the whole concept. If you like, give specific arguments about why something is or isn't a prerequisite to a specific topic using a specific approach to that topic.