If another brand launched first at same price points they simply will not get the traction Apple does.
Even with $3,500 price Apple likely needs sales hundreds of thousands of units to break even , no other manufacturers cannot pull it off
I love my Apple Watch (on my second one now) and I didn't like wearing watches. Except the Pebble that I bought (I think that I got the first generation Pebble colour, but it's been a while). After that product, things went sideways for Pebble for a lot of reasons. But the initial products were great and the build quality was good (not great, but good). The same applies to the first few generations of the Palm Pilot (and to a lesser degree, the Treo), although I think that the best PalmOS device built was the Clié NX70.
With respect to Apple's break even…I suspect that the research they did is going to produce benefits across all of Apple's product lines for the better part of the next decade (part of it already has, with the Apple Watch Double Tap hand gesture, although that is movement detection not camera-based).
They feel the need because unlike Apple others cannot wait years to release a product or upgrade to a successful one and still sell enough. Everyone else have limited brand recall, if they don't move fast a competitor will and they loose relevance.
The point is nobody else can sustainably build to standards the way Apple can, because Apple can take its time enter a industry late and still win big.
When the tech advanced, and use cases evolved, and users had become accustomed to the limitations of the apple watch style of smartwatch - which regarding battery life STILL HOLD TRUE... once all that was the case, Pebble had to deal with the "and now what?" and they couldn't.