Why is there this new wave of PKM tools like Roam, Obsidian etc

Started with this comment of mine ~ late 2020

New-fangled graph-oriented knowledge systems seem all the rage e.g. Roam and now a plethora of others Foam, Dendron, Obsidian, Athens Research etc etc (though seem incredibly similar to wikis … but with backlinks and block level linking …)

cf also the connection with the zettelkasten methodology.

#todo/writeup