Looking at offensive stats, Kobe posted merely solid efficiency on a ton of volume. Look at career PER: 23.2 and 22.8 for Kobe and KG respectively. In contrast a truly game-changing offensive player is Lebron, whose career PER is 27.7 (!!). The difference isn't due to Lebron being still in his prime; he has been more efficient his whole career than Kobe was even at his peak.
That is to say, Kobe was a great offensive player, but not a LBJ or MJ-level offensive dynamo. KG was also a great offensive player, and he changed the power forward position with his shooting, but he was never as much of a volume scorer as Kobe.
Defensively, on the other hand, is where you see a BIG difference. Bryant actually has a negative defensive BPM for his career, which probably undersells him a bit, but the fact is that he is hardly a dominant force on this end. KG on the other hand, well, we've all watched him play: no stats needed. We're talking about the difference between a roughly average defender and perhaps the GOAT.
I'll take KG.