Everyone involved in these projects and zettelkasten seems to describe themselves as knowledge workers and what they do as knowledge work. Despite a mass of evidence that could be taken to the contrary, I would never describe myself as a knowledge worker. And I actually believe it would misdescribe what I do.
I have an excellent memory over a day/week/month but I have trained myself to progressively bury the detail. When the detail is buried, I retain associations and possibilities in an ever-flowing probability matrix. Useless at University Challenge, always win at Who Wants To Be A Millionaire. This is a normal process, but many, or most, have tried to train themselves to retain detail when I have gone in the opposite direction. Some people with extreme Aspergers have a natural tendency to remember detail and work with details, but have very fixed associations, with certainties rather than probabilities. There are strengths to both approaches.
So back to knowledge work. I don't want to have a system that is detail oriented, though many people may. I don't need a system that will add flexibility although I do want one that supports it. I want a system that will store pointers to the detail.
Which brings me to the issue of tags and links. Links are always fixed and hard, even if a link network has a degree of fluidity. Tags are often described as fixed categories - but ad hoc tags can be regarded as a set of fuzzy associations. Ideally, I believe, links should be variable in strength.
Everything depends on who is using it and how it is used.