Yes but in an equilibrium steady state, compute and data advantages are all you need to first order. China does not yet have a compute advantage. RL is indeed the magic sauce for coding agents but the bottleneck for how much progress you can make, for both the US and China, is compute. The US at least for the next few years has a clear advantage here.
So, China is in the race. Just not leading yet
Exactly -- the hope for US strategy is that you can slow them down a lot but not forever. That slowing them down is in itself enough to keep a strategic advantage over them both in terms of economic growth and offensive capabilities both in terms of cyber attacks, intelligence and things like drones, etc.