What are the statistics for those?
Apple 44%
Samsung 16%
BBK Electronics 16% (Oppo/OnePlus/Realme 8%, Vivo 8%)
Xiaomi 8%
Others 16%
That's according to Counterpoint Research [1]
Profitability appears to be even more skewed in favour of Apple but I don't know the exact numbers.
It would be interesting to know what's included in that 16% others category as that's where any challengers would be coming from.
[1] https://www.counterpointresearch.com/global-smartphone-reven...
https://web.archive.org/web/20160423202414/http://www.dg.gov...
Unfortunately, I don't know what the authoritative source for company information is in China. It can't be blog posts and media reports I suppose.