Marco Arment:

The ideal smartwatch would have a high-resolution, color, self-illuminated but not too bright, highly visible yet completely subtle screen that’s always on, but isn’t tacky and doesn’t draw much attention to itself from others. The screen must be as large as possible so you can read and touch it nicely, but as small as possible so it isn’t ostentatious and doesn’t look out of proportion on a wrist. This screen, and all of the other components, must use as close to zero power as possible because the battery needs to last at least a week (ideally much longer), weigh as little as possible, and occupy almost no space.

So it needs to be bright, dim, bold, subtle, large, and small, with a battery that lasts a month with zero mass, and some compelling everyday applications beyond telling time and showing phone notifications. The true design challenge isn’t making it pretty — it’s making it good.

Seeing other smartwatches fail at these impossible challenges, many of us assumed that Apple had to be working on something different for their “wearable”.

[...]

Nope. They don’t. It’s a watch. And it’s very similar to other smartwatches we’ve seen — just executed far better. (We hope.)

Apple didn’t find a way around the laws of physics. They didn’t somehow unveil a revolutionary battery or screen technology that the world had never seen before. They punted again. In the absence of any better alternative approaches, they just did what they could with today’s technology.