I've told you already that this is not a technical matter
And I never meant it to be so since this is all about economics. You can take 1,000 independent nodes and 1 unit with the same processing power as theirs combined, and it will be more efficient on purely technical ground but it will be 10-100x more expensive than these 1,000 independent nodes.
How can that be ? If it is purely technically more efficient, that's what determines the (open or hidden) cost
You may want to learn the basics of economics. Top processors are times more expensive than the mainstream ones while their processing power may be only a dozen percent higher
Technically better doesn't mean economically cheaper
In fact, the direct opposite is almost always true. For a better efficiency you have to pay a higher price. But that's not the main problem here. The main problem is that to get a somewhat more efficient system you have to pay a significantly higher price. In short, you just don't know what you are talking about. But even that is inconsequential to the discussion. The scalability of a decentralized payment system is built in, i.e. it scales up together with its expansion (and thus its processing capacity is effectively unlimited). With a centralized system, its processing capacity remains the same, and if the number of transactions increases beyond its limits, you will have to buy new capacity. As simple as it gets. And I hope that will help you shut at last the fountain of empty verbiage you produce
You're right. That's why banking never worked, and why nobody's using facebook, amazon or google. Sorry for my verbiage, your argument is crystal clear
Apart from the economics basics, you may want to learn more about how Google is actually built inside
Banking worked in the past and continues to be working so far simply because there was no such thing as decentralized "banking" in a trustless network in the past (in the form of payment channels). Strictly speaking, we are not there yet (you should know that yourself) but for issues not related to its advantages or deficiencies. Personally, if we assume free competition (i.e. no governments with their laws), I'm inclined to think that a decentralized payment system will quickly crowd out the current banking system. In fact, I don't even need to address this issue as such since this is how Internet itself is built. To access hosts on your network you use your nearest cheap router or switch (which is able to process only a few requests per second) and you don't have to walk to the top-level nodes (which otherwise should be able to process millions of such requests per second as well as have millions of ports) just to reach out for your neighbor. In this way, Internet is also scalable without limits conceptually (if we discard delays due to signal processing and the finite speed of light). You just need to add more digits (octets) to an address pool as the network expands