The bottom line is, when you have already dominant companies with better and more complete features than your own offerings, you cannot compete and will be perpetually left behind the technology and adoption curve until some sort of protection is granted to such weaker companies.
US EDA companies can gain on China's competition only if there is a lot of room for improvement. If there's not much room left, China will catch up, in spite of the lead that American firms now enjoy.
The EDA situation may be similar to semiconductor lithography: TSMC is now ahead of China's fabs, but how much further can the Taiwanese firm go? Perhaps to 3 nm, maybe to 2 nm, and then what? They will likely be stuck, and that would allow the Chinese fabs to catch up.
The EDA market is about 40 years old, and is probably maturing. This means that essentials likely can't improve much. The US EDA developers are probably adding lots of glitz, much as US automakers added tailfins to cars; however, the essentials of the software are probably not changing much. Hence Chinese firms like Empyrean et cetera will have time to catch up.