[kbenson]

> That use is a crazy small niche, and if you really wanted to blow money on eye catching displays, there are any number of more creative ways to do so.

I'm not sure if that's supposed to be a followup to the simile, but it sounds just as likely that you've missed the point I was trying to relay, so I'll elaborate.

The point is not to wow your customers, it's to make things clear. Different tactics work for that in different circumstances. A high density phone display, an older desktop display, and a 4K desktop display may all benefit from slightly different settings such as thickness in a font. Allowing the OS to optimize for functional legibility based on device and usage specifications is a good capability, in my opinion. That the demo allows you to see how the system works easily through dynamic changes does not mean that's the intended use.

As other have pointed out, just the ability to ship one font for your website and allow it to generate the correct variation based on responsive web design parameters is itself a win in the bandwidth it saves.