Sorry, but why do you keep forcing me to analyze the problem based on the outdated ETH when ICP is at least 15.5 million times more efficient than Ethereum?
The reason I focused on ETH is because people are actually using it. You can tell me as much about how great ICP is, but unless it's actually used it's just academic theorizing. ETH is a great example because it's a great case study. Many businesses have tried to use ETH smart contracts for their business, so we have a lot of data. With the DAO case and the resulting rollback we even know what it looks like when theres a systematic failure on the system.
We do not know any of that for ICP because it's some niche development thats not really used in production by many businesses.
Also of course ICP is much cheaper than ETH, because ETH transactions are a valuable resource, because ETH is valuable. Because for ICP there is orders of magnitude less demand, the price for operations is low.
But more importantly, you focus on the transaction cost, which yes ICP changes because of it's different fee model. But the underlying problem, is still the same ICP still only has a fixed number of transactions per second globally, meaning demand rises anywhere affect the whole system. This is a fundamental flaw in the system. If demand for Tailor Swift tickets is high in the US, it should not effect the cost of ordering a coffee in Germany. No other system works like this. Amazon doesn't work like this, Visa and Mastercard don't work like this, etc. and the reason for this is that it's completely stupid.
The problem is not the absloute value if it's 25€ or 0.00001€. The problem is that there is price fluctuation of a factor 10k possible. And thats also not fixed with ICP. The only reason we don't experience this with ICP is because theres no demand like ther was for ETH.
The whole point is that your claim that it's "decentralized" is just plainly wrong. If it were decentralized, unrelated actions on the other side of the globe would not effect the operations here. This is why cash is decentralized. It doesn't matter how much cash is spent in Australia, my euro coin is still a euro coin here in Germany.
Blockchain is not decentralized. The value and transaction costs of each block in the chain depend heavily on the global state of the system.
With blockchain the chain itself becomes single point of failure.
Also your calculation is ridiculus. In ETH you don't pay per operation, you pay per transaction, independently how many instructions this executes. Meaning yes if you only perform a single Signature Verification you have this price difference, but I've never written any application that only performs singe Signature verifications without any other functionality.
But let's do the same computation for the server I rented in a datacenter: I pay 30€/mo, which is 0.00001157407€ per second. It has 10 cores with 2.2GHz which are 5.2609428e-16€ per CPU cycle. According to googles summary result performing an eddsa signature verification takes 87548 to 273364 CPU cycles, taking the upper bound this means a cost of 1.4381524e-10€ per signature verification.
And this cost is not dependent how many people are doing a transaction at the same time. It's a fixed price I'm paying for years.
But again thats a stupid example, because my server, like any real application is not just doing Signature Verifications every day. Instead they perform complex operations. So let's stick to my example placing an order, which needs the following:
1. validate the user inputs syntactically, e.g. correct email and address format,etc.
2. Validate the request integrity by computing the hash over the request and validating the signature
3. Lookup the article ID in and the availability in stock and check the price
4. Compute the total price for the order from the price of the articles from the database
5. Try to retrieve the costs from the users wallet
6. Mark the selected articles in the stock as onhold/in preparation so they are not marked as available anymore
7. Store the order for later inspection
This is much more than a single EdDSA signature. Feel free to compute how much resources this costs on either chain. I can tell you already it's orders of magnitude more than it costs self hosted on a run of the mill server, without even cosidering sudden price hikes.
Like I said, tell me a use case where on-chain provides any benefit from doing the exact same the traditional way. I do not know of any. And you are clinging onto details like the exact price, without addressing the fundamental issues that I bring up which make it inherently unusable.