Here's opinion from the horse's mouth:
Back in 1999, the mag asked Joy what inspired him to write vi:
What happened is that Ken Thompson came to Berkeley and brought this broken Pascal system, and we got this summer job to fix it. While we were fixing it, we got frustrated with the editor we were using which was named ed. ed is certainly frustrating.
We got this code from a guy named George Coulouris at University College in London* called em - Editor for Mortals - since only immortals could use ed to do anything. By the way, before that summer, we could only type in uppercase. That summer we got lowercase ROMs for our terminals. It was really exciting to finally use lowercase.
So we modified em and created en. I don't know if there was an eo or an ep but finally there was ex. [laughter] I remember en but I don't know how it got to ex. So I had a terminal at home and a 300 baud modem so the cursor could move around and I just stayed up all night for a few months and wrote vi.
Linux Mag then asked: "So you didn't really write vi in one weekend like everybody says?"
No. It took a long time. It was really hard to do because you've got to remember that I was trying to make it usable over a 300 baud modem. That's also the reason you have all these funny commands. It just barely worked to use a screen editor over a modem. It was just barely fast enough. A 1200 baud modem was an upgrade. 1200 baud now is pretty slow.
9600 baud is faster than you can read. 1200 baud is way slower. So the editor was optimized so that you could edit and feel productive when it was painting slower than you could think. Now that computers are so much faster than you can think, nobody understands this anymore.
This is from Bill Joy, who wrote vi. The last line is very much on point and mirrors my point of view: "Now that computers are so much faster than you can think, nobody understands this anymore."
Also: "I was trying to make it usable over a 300 baud modem. That's also the reason you have all these funny commands. It just barely worked to use a screen editor over a modem."
If one was given the task to write a text editor today, even one without a GUI, I would be surprised if anyone reached for some of the things Bill had to do in the context of 300 baud modems and a terminal (not window, but physical).
In the context of large projects vi/vim don't offer any real measurable gains. The fact that programmers who take the time to learn these tools feel good about them does not constitute proof of anything other than that fact.
Let's just agree to disagree and move on.