Finding product-market fit for health is a separate issue -- that's not the design department's job.
Ive's job was to design a brand-new smartwatch from scratch and he and his team knocked it out of the park.
I noticed in the early 2000s, and it has held true ever since: don't bother getting the first three iterations of a new Apple product unless you're well and truly enthusiastic about it. They always iterate, it always gets better, and the fourth go around is generally when I'll be happy with it.
One which I thought was too cool to pass up was AirPods, and yeah the first generation were really special and I'm glad I got them. The wireless case in the second generation was a nice bump, and the AirPods Pro (gen 3) are a clear improvement in every way. I did get a pair from the bad batch which started having problems with noice cancellation, but the replacement process was pretty smooth: so I conclude that if I wasn't in a hurry, the next generation, the fourth, would be "insanely great" and the right time to buy.
I don't think that any of this is due to the design either.