The Linux kernel is being developed by a bunch of enthusiasts literally on their own, it is not a commercial product.
Huawei developers are well paid. They are professionals.
Linux, even with all its poor architecture, suffers not from the quality of the kernel, but from the UI in general, because... Not a single shell comes close to the usability of Windows and the convenience/ease of installing software and configuring it. That is why, despite the status of a “free” product, Linux is still in oblivion on the market, for more than 25 years, with its pitiful 2-3% of the market.
There are no miracles - professionals obviously do everything better, because... they have a vested interest in this.