VS Code also starts in "seconds" on my machine, so if that's what they're targeting it's probably a success.
For that, a cold launch time of a couple of seconds (VS Code) is fine, tens of seconds (Eclipse, XCode) is annoying.
Opening new files definitely needs to be instantaneous.
JetBrains is amazing, but I hate waiting for it. It stops me from starting work. Maybe that's just my problem.