Well, central control is usually an advantage when it comes to scaling. Central control, and distributed treatment, is usually the most scalable solution.
Huh ? It is up and running for years. How many people have credit cards, bank cards, things like that ? Any decentralized solution can always also be implemented easier and cheaper by a distributed, centralized system, because there are central points of trust, which resolve a lot of issues that are difficult to solve in a decentralized system. So it is almost a theorem that if a decentralized system can attain a given performance, a similar, centralized distributed system can reach the same performance.
I have the surreal experience here that you are explaining that what is happening every day, cannot happen and will be too expensive ? Most buying online *is already* done with normal banking. All of Amazon's business is pure credit card stuff. Hello ? It *will be too expensive* ?
You don't get my point absolutely
Let's assume that you have 1000 users and just 1 bank (or a payment processing company like MasterCard) that processes payments. If the number of users increases 1000x and reaches 1M the processing capacity of the bank will likely get quickly overwhelmed. Even if it doesn't, the same 1 bank will have to process 1000x more transactions. Now imagine that 1 of every 10 users can process transactions in a decentralized way, and what will happen if the total number of users increases the same 1000x.
There are two points here. MasterCard doesn't have to scale up by yet another factor of 1000, because they already have a big part of the world as their customers. There is no "infinite amount of customers" and hence no unbound scaling problem. The only reason why we talk about scaling problems with crypto, is that they already saturate at microscopically tiny levels of transactions, but we don't have to scale up to the size of the universe. There's a finite and quite limited amount of customers and daily transactions to have had. When that is reached for a system, the system is good enough. It seems to me that companies like MasterCard are already covering a significant part of the market, so their biggest "scaling problem" is maybe a factor of 10, in their wet dreams.
The second point is what I already said: if a decentralized system can do it, a centralized, distributed system can do it too. Take your "one out of 10 users" and replace that by a node belonging to the distributed system. Hell, maybe the bank can find an agreement with one out of 10 of their customers to have a terminal in their house ! In the beginning, this is how commercial internet got started: certain ISP just gave free internet access to customers, if they could install a rack of electronics in their basement, so that they had calling points all over the place. I have an ISP that uses my home router also as a WAN emitter for customers passing in the street. But this is a centralized, but distributed system.
The only difference between a distributed, and a decentralized, system, is political, or in other words, who knows the "admin password".
You talk as if you have been frozen for the last ten years, and when you are told about Bitcoin, you say that it is impossible