I don't think that's what he is saying. He is saying that Emacs once ruled supreme because it was the only option. Now that IDE's have caught up, it's in the lead by only a little.
I'd say still by a lot, but yeah, IDEs have advanced in the last 20+ years (and one of the main advantages of something like VScode or IntelliJ is that it does a lot "out of the box" and it's pretty discoverable).
