Then, we have had decades to observe whether this approach (that I assume to be familiar to at least many in his field by now) actually made sociologists more productive (at whatever it is that sociologists do), or not.
I tried Zettelkasten, but I think it’s a good solution to a problem I don’t have. I take notes to remember and find information, not to publish it. ZK is more geared toward sharing with others.
No, ZK is only for you. It's like a personal wiki which you use for thinking.
I think that’s much closer to “Linking Your Thinking”. Short version: your PKM is a wiki. Make lots of index pages like “Restaurants Index”, with a master index that maps to all of them.
ZK wants to apply a linearity that just isn’t relevant to the things I want to record.
Luhmann also used lots of index pages in his own original Zettelkasten.
It's also important to keep in mind that in the kind of research he did, concepts were a bit shorter.
https://en.wikipedia.org/wiki/Zettelkasten