American space technology is definitely dominate the world at the moment. SpaceX and Falcon heavy and next generations of rockets engines will be incredible. If they deliver what is promised. China along with everyone else is also progressing but everyone at different rate. Long March 5 is a good rocket for China because it is currently China's most heavy lifter until Long March 9. I believe the research teams are trying to develop different propulsion to try and catch up to USA's lead in those research fields. Cryogenic engine technology now left to the standard engineering teams.
CAS higher ups and labs are looking at alternative methods of propulsion to catch up to Americans. Otherwise stuck forever with conventional rocket engine even if we manage to get closed cycle and ability to use different fuel types with closed cycle. This will forever limit what humans can do with space. But Chinese researchers have only not long ago started making more investigations. Rockets are still best, most reliable and cheapest to get something into earth orbit and into sun orbit. After that, they need to play with different technologies. So yes LM5 is indeed good for China now but it is no Falcon heavy. We will have heavier lifters in future but primary concern with delivery systems now is affordability and how quickly it can be manufactured. Landing rockets could be another area for development to cut costs. Space station, research labs, and moon human landing and base are all big future space projects. No point to have xx ton lifter if it is expensive and takes years to build.