For Apple, I haven't checked all the details, but the logic should be sound.
1: Due to the lithography limitation in China, it looks like Apple would always have better logic and memory chips. With AI features moving to edge devices, Apple's enhanced computing power(M4 chip is a beast) becomes more appealing. Satcom/Photography noncore functions.
2: IOS is a much more mature and huge ecosystem, I doubt foreign App/Game developers would migrate their products to the HarmonyOS, I guess there are "emulators" that can be used to run Android apps in HarmonyOS. Lack of App/Game support is a no-go for lots of people. Unless Huawei is able to vastly ramp up advanced node production, then flooding the market with cheap, high-quality devices, without much higher market shares, very hard for HarmonyOS to compete with IOS.
3: Global after-sale support and brand awareness, I doubt people can get after-sale service outside of China.
4: I saw some people posting on social media, with multiple discounts, Apple iPhone 15 Pro 256G is selling for around 6300RMB in China, the same price level as Mate 60 Pro, Unless people want to support Huawei, there are no compelling reasons to buy Huawei over Apple when they are on the same price level.
If you are a light phone user, just check social media posts or watch videos on TikTok, any phone would do the job, won't notice any difference.
For Nivida,
1: H20 and 910B prices similarly in China, 910B maybe slightly faster, but H20 is manufactured by TSMC with better processing nodes, H20 should be more mature and stable.
2: Nivida's CUDA ecosystem is so entrenched, without the geopolitical risk factors, so much easier to build your system with CUDA. Recently some news mentioned some big tech companies are planning to build data centers in the West (or rent AI chips) to avoid the sanctions in order to buy Nivida's chips.