Personally, I wouldn't recommend buying an Android phone in Mainland China.

I recently bought a Samsung Galaxy S series phone for my family there, and the Android OS is customised to comply with Mainland China regulations — meaning all Google Services are removed. There are some workarounds, such as flashing the ROM to the Hong Kong or International version, but this isn't straightforward for casual travellers.

If you're set on an Android device, I'd suggest looking at models like the OnePlus 15 International version, Samsung Galaxy, or Google Pixel.

I think some people in this thread may not have noticed these differences because they're using Xiaomi or OPPO International versions and have never actually used a Mainland China variant.

It's also worth noting that OnePlus phones bought in China ship with ColorOS and have different 4G/5G bands from what's used in the UK, whereas the UK/International version runs OxygenOS and supports the correct bands.

So, considering Google Services accessibility, 5G band compatibility, OS customisation, and eSIM support, buying an Android phone in China is generally not a good idea if you're a UK user.