Can you describe what you think vimwiki adds over a bunch of markdown files and `gf` for links?
Or you can be lazy and install a plugin that takes thirty seconds to get the hang of.
Actually writing and staying organized has been challenging due to the fact I don't focus well. Spending time recreating vimwiki is time not spent staying organized. Vimwiki has low friction so I use it.
I suppose that it is not that difficult to recreate the basic behaviour of vimwiki with custom commands and navigating with `gf` between your notes. However, for me vimwiki provided an easy way to get started in an environment where these commands were provided out of the box. Since then, I have gotten used to, and somewhat attached, to vimwiki and have kept using it.