I used to use terminal windows separate from my editor. Now I use VSCode, I have 6 different but related projects open. In VSCode this means 6 windows, each with multiple tabs etc. In each of those are 1 to 3 terminal editor windows. That means when I switch to that project, shells related to that project come with it. No having to hunt through 6 to 18 terminal windows to find the correct one(s)
Turns out, for me, the terminal emulator embedded in the IDE has been a big plus.
I'm not commenting on other IDEs - I honestly wouldn't say I was really even familiar with VSCode, I've generally only used it from time to time when doing embedded stuff.
The original comment was aimed at Xcode though, and it's in that context that I'm (still) struggling to see why you need a terminal.