[shanusmagnus]

Sounds a bit like Gingko, which I used to really love:

https://gingkowriter.com/

[swah]

Same, I really loved that they finally innovated on text editing interface. Couldn't get used to be honest.

As usual, there's an Obsidian plugin nowadays trying to mimic (some of?) it: https://github.com/ycnmhd/obsidian-lineage