Ethernet longer than 328ft.

I'm a software engineer with basically no understanding of ethernet when it comes to hardware. According to the Wikipedia page on Cat6 the maximum length of Cat6 is 328 feet. So how does something like this 328ft reel work? Wouldn't connecting a device put the length over the limit? What about this 656ft reel? That's certainly over the cited limit. Not sure if it matters, but my use cases are HDBaseT video, a digital audio snake, and a MIDI snake.