What is holding back other technological countries to compete head to head with these giants? Silicon Valley?
From a technological standpoint... nothing is preventing other countries from competing...Economically however, have you seen the costs involved in manufacturing in "First World" countries? There is a reason the majority of items you'll find in a lot of stores are all marked "Made in China" (or some other SE Asian country)...
And then there is the enormous costs involved with the production and supply of electricity... If other countries had similar manufacturing and electrical supply costs to China, you can be damn sure that there would be massive mining operations in those countries as well...
Moreover, most electricity for mining in China is probably stolen.