Might be but the ROI certainly isn't. That's why I use one large text file also. One relevant detail is not to consider that file read only, you must tree shake it regularly. Noise will be less and relevant stuff will be easier to find.
What's the best way to go about it in your eyes?
I don't dive into "implementation details" but you might find something here: https://github.com/slowernews/hamster-system#hamster-flow
2) I can link the notes to create a sort of personal wikipedia. So far I'm pretty happy with Zettlr for this purpose.
I find that even if I don't have to go back to many notes or actively walk through the graph it's really useful for distilling knowledge.
Anyway, I used grep too, but I also navigate by following the links in my notes, which can sometime take me to different location. That can be a single file too or multiple files. That doesn't matter. What matters more is organization(or rather lack of).
With Zettlekasten, you build a concept map of topics that you wouldn't otherwise get if you write your notes linearly or chronologically.
So yeah, zettlekasten doesn't make sense as a productivity system, but that isn't its intended use case anyway.
I tried it, and for me it is not.
The ideas stored are too granular, and the linking becomes unwieldy after a while.
I'd rather store small ideas in a linear big txt file (I use Google Docs), revisit parts from time-to-time and collect/coalesce similar ideas and rewrite them into bigger ideas.
This process of reviewing and rewriting has allowed me to cluster ideas and gain clarity over time. Inspiration is lumpy so everyone needs a cache of thoughts. But these ideas also need to be regularly iterated upon and synthesized into coherent narratives if they are to be useful.
This seems to be a low effort, high reward way of doing things. What extra benefit does Zettelkasten bring and is it worth the additional effort?
EDIT: Another consideration is that you don't want the time you dedicate to sorting a productivity system to be especially big. You want to make stuff. The big txt file doesn't take up a lot of time to organise and allows you to spend time doing good things.
[1] https://news.ycombinator.com/item?id=22276184 (entitled 'My productivity app for the past 12 years has been a single .txt file')