when a tool is fast (very fast) it becomes extension of thinking
I suspect there's something similar happening here to how mind extends over the hammer/pencil held in hand, and the mind merges the two together
thinking by writing makes it easy to think, as there's very small latency to putting things on paper / in text buffer - you don't think about the tool/medium, you think thoughts and use the tools to put them in writing
that's why CLI/REPL interfaces usually feel better - they give immediate feedback (cli ux)
sidenote, but it's sad that we still can't build fast UIs in 2020
Andy Mathuschak mentions performance being important for digital reading:
Skillful reading is generally non-linear, but digital reading experiences often make rapid scanning and referencing more painful simply by being slow.