Apples to oranges comparison. VS Code is a text editor whereas Xcode and Jetbrains are IDEs. The real comparison should be with Sublime Text vs VS Code. Sublime Text blows VSCode out of water while opening the same project folder.
Here's a naive comparison
~/workspace/iOS Project(develop)
time subl .
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Executed in 75.46 millis fish external
usr time 21.45 millis 106.00 micros 21.34 millis
sys time 14.84 millis 659.00 micros 14.18 millis
~/workspace/iOS Project(develop)
time code .
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Executed in 4.18 secs fish external
usr time 123.39 millis 99.00 micros 123.29 millis
sys time 175.07 millis 585.00 micros 174.49 millis
With the C/C++ and CMake Tools extensions installed, VSCode is an IDE that provides pretty much the same features as Xcode (for some features Xcode is ahead, and for others VSCode).
XCode needs about 12 seconds to start into a C/C++ project (on my mid-2014 13"MBP), while VSCode needs 3 (and yes I start into both fairly frequently from the command line). When actually working in the IDEs, for some things XCode feels slicker, for others VSCode. All in all, XCode really isn't a good argument in the whole "Electron vs Native debate" (and the same is true for VSCode vs Visual Studio btw).
Here's a naive comparison