Fair enough. When I worked for Apple, I would often take a gander at the iOS source code. There was a lot of legacy stuff in there, as in, "do not modify this method, we don't know what it does" in comments. There were certainly legacy components in there from many years back, and it didn't seem like tech debt was on the radar. At least when I was there.
Certainly there are various bits that are legacy and behave like that, but generally speaking, calling the entire thing legacy is a bit of a stretch. Also considering it started in 2007, I think the definition of legacy is quite short termed here. It also implies a negativity, that if you’re not jumping from technology to technology then you’re doing something wrong. I disagree with that viewpoint.
As someone currently taking a break from reverse engineering the internals of CoreGraphicsServices on macOS, I can't resist saying that iOS can't possibly be as legacy as this.
