Noise depends a lot on the actual amount of light hitting the sensor per unit of time, which is not really a part of the simulation here. ISO 1600 has been quite usable in daylight for a very long time; at night it's a somewhat different story.

The amount and appearance of noise also heavily depends on whether you're looking at a RAW image before noise processing or a cooked JPEG. Noise reduction is really good these days but you might be surprised by what files from even a modern camera look like before any processing.

That said, I do think the simulation here exaggerates the effect of noise for clarity. (It also appears to be about six years old.)