Once you predetermine the categories, it gets difficult to connect ideas from one category to another — let alone multiple. Each idea becomes a rigid part of its category. It’s not a problem to have categories (it guides how you tag notes, for example) — I’m saying the rigidity becomes a problem.
ref: https://leananki.com/zettelkasten-method-smart-notes/#Keeping_Up_with_Information_Overload