If local demand is covered by Chinese phone manufacturers then thats a win for China.Chinese don't want Samsung. (<1% of market). They are only leaving the semiconductor fabs and R&D facilities,
Market demand is very flexible for consumer products. 3 nm is already going to be far more expensive than 7 nm, while 7 nm with 3D packaging is likely to have similar performance, maybe a little more battery consumption. Then add a little tariffs for Trump reasons, and they're now unaffordable. ez pz. Consumers can't tell the difference and one phone is double the price of another, easy choice.
Now if they are expanding their R&D centers in China then thats another win as these facilities contribute to the innovation ecosystem