Apparently you measure success by "besting the single greatest consumer product success story in a generation". By this metric, virtually nothing would be considered a success.
Meanwhile, Apple became the biggest watchmaker in the world as of 2017. After only three years of producing watches, they unseated literally every other watchmaker in the world on revenue. That seems pretty damned successful to me.
You might also be surprised how many are knockoffs [1] which are rapidly improving in quality [2]:
[1] https://www.macworld.com/article/3311456/airpods-knockoffs-t...
Samsung Buds OTOH stay in (and don't have the daggy bits hanging out).
https://en.wikipedia.org/wiki/NRS_social_grade
The amazing thing about the classic Apple designs was the way they managed to be textbook Veblen goods while also appearing to be gender and class neutral. They were aspirationally expensive, but not blingy.
That changed when gold and pink started to creep into the design vocabulary and the prices started moving up. The classic designs were more democratic. Not everyone could afford them, but they managed the neat trick of appearing to be visually inclusive rather than aggressively exclusive.
From that POV, Watch has been a design failure. It lacks the social status of the high-end I-have-money watch brands. It's neither expensive-but-neutral nor an outrageously self-indulgent statement product. The expensive straps and stainless steel variants made a pitch for the latter, but it was never convincing.
As a signifier it's visually bland and even slightly vulgar, which is why it hasn't had the same cultural impact. It's also why it works for C1/C2s but not for the ABs. Sales may be fine, but in its current form it's never going to be the covert high status product that Apple used to do so well.
Apple is much more in line with a premium brand driven good like Nike, or Sony.
A true Veblen good phone would cost like $20000, be gold cased and nobody you know would own one.
https://en.wikipedia.org/wiki/Vertu
[Only ever saw them on sales at Heathrow Terminal 5 and Courchevel 1850]
How do you measure success? Because there is no way any comparison with the number of people who own an iPhone or any other kind of Apple device. Even in Japan where Apple has the lion share of the smartphone market I hardly see people with an Apple watch.