The issue here is how much will ping time add to that when streaming a game. Consoles hover in the 100ms are depending on game. PC's it's highly dependent on video hardware, but I good gaming system, display, and keyboard/mouse will be around 70ms.
The issue of streaming game ping ms in part comes down to human reaction time, which averages around 200ms-250ms. Given this, you want a ping time that doesn't add enough latency to the setup to put you above that 200-250ms reaction time, or you start to perceive more noticeable input lag. Given 70-100ms baseline, you want a bandwidth ping absolutely no more than about 100ms on top of that.
The math squares with my personal experience as well. I've played a few streaming services, and when my ping gets to the 100ms area I start to notice a little difference. It's often sill playable, but if it gets higher it can be very distracting.