[...]
Yes, there will likely only be around 10 billion people on the planet, but that's a hell of a lot of transactions. At one transaction per person per day you've got 115,700 transactions per second. Sorry, but there are lots of reasons to think Moore's law is coming to an end, and in any case the issue I'm most worried about is network scaling, and network scaling doesn't even follow Moore's law.
Making design decisions assuming technology is going to keep getting exponentially better is a huge risk when transistors are already only a few orders of magnitude away from being single atoms.
[...]
Moore's Law predicts the performance of a
single CPU. In terms of bitcoin scalability, it doesn't matter how fast a single CPU will be 10 years' form now.
Rather, the crucial measure is
cost per CPU calculation. Transistors may be reaching physical limits, but in terms of producing CPUs more cheaply (and thus in greater quantity), and in terms of energy efficiency, there are still many orders of magnitude of growth potential.
There is no reason why a bitcoin node can't run on a multiprocessor machine.