It's been done with the Stinger - since 2017.
Really depends on which car you pick from each stable.
You certainly cannot pick any Stinger/Genesis to go up against a Giulia Q.
The 3.3GT AWD vs the Giulia 2.0T Q4 Veloce is maybe a reasonable comparison, and the Stinger has it by a whisker based on 90 more HP (is also slightly more expensive than the Alfa in that trim), and for equal money I'm sorry but the Kia isn't going to get my business.
Head to head, here:
http://www.zeperfs.com/en/duel6976-6552.htm
The performance difference is more telling (in favour of the Stinger) when comparing base to base, but again the Stinger is the more expensive car.
http://www.zeperfs.com/en/duel7081-6761.htm
(those are European list prices, so maybe the US market is different, and I went with the Stinger as its prices are on that site whereas the G70's not yet).
I suspect that in the used market, the cars will be fairly similarly priced. That's when you need to decide in your own mind if the Koreans have "made it" into that echelon yet or not. I think they are close, and things like a wide dealer network also work in their favour. But I'd have to really love the test drive to buy a Kia/Gensis over an Alfa at the same money, let alone a premium for the Korean. YMMV.