Gartner is pure speculative data
Why are you basing this data as factual?
Gartner predominantly speculate, not give cold, hard fact.
The launch of the iPhone 12 massively distorted the smartphone market in Q4 2020 with the new 5G-capable mobes sucking oxygen from rival Samsung. Gartner stats show sales of iPhones to end users grew 15 per cent in Q4 2020 compared to the previous year, with Apple shifting nearly 80 million units. Apple's quarterly market …
Assuming this is true, since there are effectively only 2 mobile platforms, Android and iOS, and you can only get Apple gear from one manufacturer, it's amazing that Samsung held the top spot this long.
As an Android user, I like the look and feel of the 12, as well as what's under the hood. Finally another device from Apple that actually fits in your hand without needing a case. It has tempted me to go to the dark side more than any other device from Apple. But it still runs iOS, which for me is still a deal breaker. YMMV.
Also from the write up, it would seem that Gartner had not fully taken into account the US sanctions against Huawei and the % market share distortions this was introducing into the marketplace. Plus we shouldn't forget about the effects of the "5G" pixie dust.
Not saying the iPhone 12 wasn't a good product, but there is alot more to this than Apple good, Samsung bad.
The I-Phone 12 was also a heavily touted "supercycle" update for users who'd held off from some of the poor decisions in the 10 and 11. And, no doubt in the US, there were some people wondering what to do with their governement cheques.
All great phones, but are not reaching the point of peak utility? Obviously not if people are still prepared to hand over so much for a beautifully packaged computer they hardly ever use.