I think the technology of blockchain is irrelevant.

If something can be accomplished on the blockchain, which requires N nodes, a business can probably replicate that same objective with less than N nodes because they don't have to pay the cost of verifying that nodes are acting honestly. This business is incentivized to be honest because otherwise they lose their business. Someone has to pay those costs for the N nodes on the blockchain - who will it be? Transactions seem cheap now because funding for these blockchains is often used to subsidize costs.

You mentioned ease of use, like the use of SDKs, but blockchain technology does not enable that. All blockchain can do is that if you ask it "hey i was told the state of the world was this. is it true?" and the blockchain will tell you yes or no. If you want to provide those kinds of guarantees to customers in a reliable way, all you need is cryptography, not blockchain.

The most important aspect of blockchain that is relevant here is that your counterparty half a world away and you both agree that you trust the state of this blockchain, and thus can transact on it.

For business running the same code on their 1 node instead of N is not a replacement, because their counterparty has no reason to trust whatever is running on that 1 node.

Your reasoning re: N nodes are expensive is also flawed. Executing a single payment transaction takes a fraction of a second of compute. Even if it is replicated 10,000X, it's still extremely cheap compute-wise. The low cost of transactions has nothing to do with subsidizing.

I don't like Blockchains mostly but the technology of the Blockchain here is not irrelevant, it is a way to use peer to peer liquidity. That is there is no need for a central entity to have liquidity in many different circuits because you can trade with other coin holders directly in many different exchanges.

Sort of like banks use customer money to offer loans to avoid the need of centralised liquidity.

The Blockchain technology is important to allow different exchanges to interact with each other in ways that I suspect would be not super legal through a central entity.

Is this just for dilution of responsibility? If a central company is responsible for these transactions, then they are responsible for the transactions, which means there are all kinds of legal constraints and repercussions. But if it's a blockchain, then all of the nodes in the network are responsible.

So in this case, "this business is incentivized to be honest" might be the precise "problem" this is meant to solve.

This makes sense as long as

> This business is incentivized to be honest because otherwise they lose their business

is true. And it might be true if you assume perfect competition, low barriers to entry, no egregious regulations, no regulatory capture, no bundling to force decisions regardless of 'honesty' (or 'fairness'), etc.

So in a perfect world, maybe. But I think the niche in all the imperfections.

You are missing the "trust" element of a blockchain. A blockchain essentially allows you to run a distributed database where the different actors don't trust one another. Tradfi is built on trust of entities (can I trust this bank? Can I trust this central bank? Etc.)

> Criptography

You mean criptography and trust right?

> If something can be accomplished on the blockchain, which requires N nodes, a business can probably replicate that same objective with less than N nodes because they don't have to pay the cost of verifying that nodes are acting honestly. This business is incentivized to be honest because otherwise they lose their business.

This is missing something important, which we can see by considering one of the major problems merchants want to solve right now.

The credit card companies charge them ~3% and then give ~1% back to the customer, implying that there is a ~2% net gain to be had by cutting out the middle man. So why hasn't this happened? Because the alternative with the lower fees is ACH, but customers are less willing to give out their bank account number than their credit card number to a random small business.

This is the easy case for some centralized service to fix it, right? Have some large trustworthy company take the customer's bank account info and transfer the money to the merchant for a very small processing fee. But this is the part where your assumption falls through. Once the merchant has signed up for this, the payment processor is the only one with the customer's payment info. In other words, it's hard to switch, and then the payment processor can charge higher fees (eroding the benefit) and the high switching costs also cause the market to consolidate. And because you're tied to a single payment processor, when their fraud AI has a false positive they can erase your business overnight by locking you out and not answering the phone.

Now suppose you don't have a centralized system. Instead, the customer acquires a store of value (Bitcoin, stablecoin, something else) however they want. Customer A can get it from Coinbase, Customer B can get it from Stripe, Customer C can get it by selling something on eBay and accepting it as payment, and the merchant doesn't have to do business with any of these third parties to accept payments from customers who do, because they all support the same transfer medium.

Now you have a competitive market. Currently a new payment processor has to earn the trust of a large enough percentage of the general public for merchants to be willing to use them; a new exchange would only need the trust of enough people to be doing enough business to cover their costs, a far lower threshold. If a merchant wants to switch payment processors or has a dispute with one of them, their own customers wouldn't have to do anything different because the means customers use to convert dollars to tokens is independent of the means merchants use to convert tokens to dollars.

> Someone has to pay those costs for the N nodes on the blockchain - who will it be?

That's the boring question. The interesting question is, can you have a blockchain with lower fees than payment processors currently have? And the answer appears to be yes, e.g. the transaction fee for Bitcoin Cash is around a penny.