I wouldn't exactly say it was a failure, all those chips ended up being used in the Nintendo Switch
There are almost 5 billion smartphone users; sales of 300 million a year would imply that those are only replaced every 16 years, which is obviously absurd.
On a separate note, speaking of the average lifespan of a phone, I'm fairly sure that with how expensive they're becoming, smartphone lifespans are increasing. Especially with:
* hardware performance largely plateauing (not in the absolute sense, that of "this phone can do most of what I need")
* the EU pushing for easy battery and screen replacement and also for 7 years of OS updates
* the vast majority of phones having cases to protect against physical damage
I'm always a little surprised that Nvidia is _so_ highly valued, because it seems inevitable to me that there is a tipping point where big companies will either make their own chips (see Google) or take the hit and build their own giant clusters of AMD or Huawei or whoever chips, and that knowledge will leak out, and ultimately there will be alternatives.
Nvidia to me feels a bit like dot-com era Sun. For a while, if you wanted to do internet stuff, you pretty much _had_ to buy Sun servers; the whole ecosystem was kinda built around Sun. Sun's hardware was expensive, but you could just order a bunch of it, shove it in racks, and it worked and came with good tooling. Admins knew how to run large installations of Sun machines. You could in theory use cheaper x86 machines running Linux or BSD, but no-one really knew how to do that at scale. And then, as the internet companies got big, they started doing their own thing (usually Linux-based), building up administration tooling and expertise, and by the early noughties Linux/Apache was the default and Sun was increasingly irrelevant.
No, that's not really why. It is because nobody else has their _ecosystem_; they have a lot of soft lock-in.
This isn’t just an nvidia thing. Why was Intel so dominant for decades? Largely not due to secret magic technology, but due to _ecosystem_. A PPC601 was substantially faster than a pentium, but of little use to you if your whole ecosystem was x86, say. Now nvidia’s ecosystem advantage isn’t as strong as Intel’s was, but it’s not nothing, either.
(Eventually, even Intel itself was unable to deal with this; Itanium failed miserably, largely due not to external competition but due to competition with the x86, though it did have other issues.)
It’s also notable that nvidia’s adventures in markets where someone _else_ has the ecosystem advantage have been less successful. In particular, see their attempts to break into mobile chip land; realistically, it was easier for most OEMs just to use Qualcomm.