I don't really think about it as linking notes. At least, "creating links" isn't the goal. Mostly, I'm trying to explore what I'm curious about.
I create links in two situations: (A) when I'm reading someone else's content, or (B) when I'm working on my own content.
When I'm reading someone else's content, I want to understand what they mean. I try to do that by building on other things I know. I also want to think further than the author. Apply it to my context.
When I'm creating my own content, I want to build on ideas. Refer to examples, compare to other ideas.
I primarily use backlinks as a method of tagging and finding my notes easily using queries. I just write and link without thinking about it too hard. After all, Zettelkasten is for effortless and fluid writing; to transfer your knowledge digitally, and use it to offload mental work to something more spacious.