My bet is that the nexus of all the innovation is still here in Silicon Valley. Many attempts have been made to replicate the environment and echo the systems that most people believe make and keep Silicon Valley at the front of the pack. We are still number one.
In addition to environment and systems, there is another ingredient that is uniquely optimized in Silicon Valley that is very difficult to replicate and keeps us resilient. It is not a thing, or a defined resource; it is a mindset and the principals associated with it.
I believe a huge contributing factor is the Valley's generous permission for entrepreneurs to fail. It's okay if you fail - dust yourself off and try again - failing is good. Lessons learned from failure have immeasurable impact. Often we hear about how lives have turned around after a failure or major setback in life. It is very common to see investors writing checks to entrepreneurs who have tried and failed in the past. In most countries and other states, failure is strongly associated with shame and even sometime exploited by others for false self-assurance. Not here. The most recommended advise to entrepreneurs is to "fail fast and often". Innovation doesn't happen according to plans and on a predictable schedule. Pushing limits and exploring the world of new possibilities is by definition built on risk taking.
Another example is the supportive attitude that exists among the inner circles of entrepreneurs and investors the Valley. This attitude is founded on a mindset of abundance rather than one of scarcity. People want to help, and they do - people and groups are cooperative and collaborative; they are not attached to the practice of keeping each and every opportunity for themselves as often occurs elsewhere. In Silicon Valley people want to "expand the pie" instead of hoarding their pieces and keeping them isolated and covered by fear of loss.
I commonly experience that once entrepreneurs step into a venture fully (I mean all the way), with passion, belief and conviction of their ability to achieve it, they attract help. Others are inspired and their innate desire to contribute for the sake of contribution, rather than for the expectation of personal gain; that special mindset of "go for it and how may I help" that is uniquely optimized in the Valley manifest itself.
So much to do; so little time! I, for one, am grateful to be doing it here.