I've been playing games since I was 2 or 3 years old, I've played "violent" video games since I was, i dunno, 13 or something, and i honest to God had to skip over the suicide video using his time stamp. When he was explaining what the video was, I actually knew I wouldn't be comfortable seeing it; seeing someone take their own life. And I think to me, that speaks volumes for how true this video is.
When I see a standard, cannon-fodder death in a video game, it's like destroying the ships in Galaga, it means nothing. Sure, video games can make a death feel sad, by building relatable characters with well-developed stories, but that's the thing, they can make them sad, but they'll never really make our stomachs turn, our make us physically uncomfortable like you would be with a real death.
I'm not even sure gamers themselves are "desensitized" to video game violence, I think anyone would be able to pick up a video game, shoot a bad guy, and be perfectly fine. Like Jim said, the brain can tell the difference. Even the most grounded and realistic game can't make death seem real, it's just impossible with pixels and lines of code, thankfully.