My guess is that most providers are using pretty much the same technology under the hood (outside of China) so the only way to differentiate yourself is by a lot of marketing and buying YouTube ads/sponsorships.
On the China side they can do two things.
- Actually hire people with expertise and get it to work by building a custom China solution
- Just claim it works in China without doing anything and spend marketing dollars so that people will say it does.
Obviously 2 is easier than 1.