I've created more than a thousand evergreen notes in about two years. This has been very useful in my learning and exploration, without a doubt.
However, I don't feel that the practice of taking evergreen notes significantly improved my mental ability to "connect the dots":
After taking an evergreen note, the usual practice is to think what already existing notes are related to the new note, and link them. I often struggle to recall more than a single related note. However, through that first link, I can explore the "link closure" and often find many more related notes.
I regularly create a note and then through related links, I discover that almost exactly the same note already exists. I completely forget about it when I create a new note.
Unfortunately, I don't have statistics of the graph of my notes, but I'd expect the average number of links to be 6 and the median is 3. For me personally, this graph is a really valuable body of information and links. I'm often amused to explore it as if it was not me who wrote it.
These observations make me think that I create an interesting garden of evergreen notes which is, however, weakly related to the mental maps of concepts, or Reference frames as Jeff Hawkins calls them in A Thousand Brains. In other words, evergreen notes don't fulfil the role of gardening and shaping my mental maps, and thus don't improve my "bare" thinking (thinking that I can do without consulting to my web of evergreen notes.
Related: