I suspect a major factor in keeping the Lightning stuff is also because of how intense the complaining would be if they switched it to USB-C. The introduction of Lightning got endless negative PR over all the old 30-pin accessories, and this would be that plus the extra complaining about how they keep "constantly" changing it.
For similar reasons, I suspect there's at least some factions in Apple that would be secretly pleased with a mandated switch to USB-C, because then they'd be able to get past it by redirecting any complaints to the government involved.
It's not quite an apt comparison because the vast majority of people already own USB-C chargers and accessories, whereas lightning was a brand new thing.
Also if Apple were that bothered by complaining, it would not have taken them 5 years and 3+ years of service programs to replace their laptops' butterfly keyboards with regular scissors switch keyboards.
The vast majority? I suspect that is very very wrong. I own a single device that has a USB C port, and no peripherals that connect to it without an adapter, and I post on HN. It is very early for USBC yet.
So, you found a phone released in 2017. From Huawei. Super cheap. That isn't even sold in the US. Where all the reviews read:
"Honor 7X has the distinction of being one of the last phones to feature a micro USB port for charging instead of USB-C. Blame the price if you must..."
For similar reasons, I suspect there's at least some factions in Apple that would be secretly pleased with a mandated switch to USB-C, because then they'd be able to get past it by redirecting any complaints to the government involved.