I'm actually very surprised that China seems ready to spend the money necessary to develop the technology for a VSTOL fighter.
I guess this will cost many billions and I don't see how the technology can be used in other aerospace projects (contrary to say general turbofan or turboshaft research).
In order for this investment to be worth it, they would need to build quite a big number of VSTOL fighters and I simply can't see the need for a lot of them. China doesn't have any ships to use them on and if they want a lot of small aircraft carriers it might be easier to build something like
carriers.
When Britain built the harrier they expected to build a lot of them so they could use them as CAS in Europe in case the soviets destroyed all the runways.
I don't think the chinese leadership is paranoid enough to consider a similar scenario.