> In the UK, we now have "Open Banking". Which means my bank offers an API which I can plug into. It also means that loads of 3rd parties can now offer banking services on top of the "centralised" core.
> So, in a way, a decentralised system is being built on top of a centralised system.
Why would offering an API mean that the service is decentralised? It doesn't - it just lets you get some data in or out. You are still beholden to a single party that can cut you off at a moments notice.
> I'll also note that - in my opinion - Blockchains aren't really decentralised. There's no way you can do an "Off-Chain" transaction. Everything has to be recorded on a single ledger.
Not true at all. Bitcoin has a Layer 2 solution where transactions are done off-chain in a non-custodial manner. Those don't need to be recorded on the ledger, only the settlement is (if you decide you do not wish to participate any longer).
This is definitely true in EU (and presumably in UK as well). If your bank doesn't like the businesses you're interacting with, e.g. gambling sites or cryptocurrency exchanges, they can close your account without notice or recourse.
And even if your account doesn't get closed immediately you are still subjected to invasive KYC procedures, even if you haven't done anything wrong. Failure to comply of course leads to your account being closed.
Any particulate service agreement isn't decentralized necessarily (I am still using one central bank), but the market is (I can change providers if I choose).
A _standardized_ API would allow providers and consumers a choice, which distributes the power to some degree and can encourage the parties to make choices that support the entire ecosystem rather than just their own ends.
Why would offering an API mean that the service is decentralised? It doesn't - it just lets you get some data in or out. You are still beholden to a single party that can cut you off at a moments notice.
> I'll also note that - in my opinion - Blockchains aren't really decentralised. There's no way you can do an "Off-Chain" transaction. Everything has to be recorded on a single ledger.
Not true at all. Bitcoin has a Layer 2 solution where transactions are done off-chain in a non-custodial manner. Those don't need to be recorded on the ledger, only the settlement is (if you decide you do not wish to participate any longer).