Can anyone imagine ANY uses for a centralized blockchain?
IOTA uses tangle, but the idea is the same. Storing immutable data.
I understand Bitcoin, people commit currency fraud. Bitcoin is decentralized. Trustless currency sounds fantastic.
I do not understand these data coins that are centralized. It isnt trustless, and at this point, why not store in a write only sql database?
Why dont they just use any SQL database? No one would be buying their coins if they didnt lie and glitter their Coordinator around with "the tangle" and "muh quantum safe crypto hash function which is broken by rookie level cryptoanalysis".
Probably because the project wouldn't have seen funding without "blockchain" in the proposal title.
Sure. A centralized chain can be used for anything that a decentralized one can be used for (with one exception [1]), you just have to trust the provider.
[1] The exception is that a decentralized chain cannot be used to fairly distribute rewards to the participants in a decentralized protocol. That makes it harder to use a centralized chain as money because you need a separate mechanism for controlling the money supply than the one that maintains the ledger. In a distributed chain, the same mechanism serves both purposes.
Note also that many systems are sometimes erroneously referred to as using blockchains, for whatever reason (misunderstanding, marketing, etc.). Leaving aside the debate about how decentralised it is, the project you mention has a distributed ledger, but uses a Directed Acyclic Graph (which they call a tangle) rather than a blockchain. Similarly "permissioned blockchains" or "private blockchains" aren't really blockchains in the strict sense because they don't need a consensus mechanism (indeed many now call themselves Distributed Ledger Technology systems).
[0] https://nvlpubs.nist.gov/nistpubs/ir/2018/NIST.IR.8202.pdf
Essentially, users money is kept in the public Ethereum blockchain so all the cryptoeconomic security properties are assured but the games are developed (and played) in a centralised side-chain using a technique called Plasma that doesn't charge users per tx and has very fast block times (~1 second iirc).
Plasma is a way of extending (for scalability or any other reason) a main-chain such as Ethereum with a new app-specific or industry-specific blockchain, in such a way that the users can always trust their money without having to fully trust the side-chain owner's best intentions.
+I've no idea if this actually happens, just trying to paint a general picture of crazy band aid stuff that happens.
I haven't seen any compelling use for either a centralized blockchain (i.e. one entity controls committing the blocks) or a closed blockchain (i.e. access is limited to a group all of which have known identities). Only in the open, peer to peer, case does it seem to have any value at all.
You can replace the word "blockchain" with "database" in this sentence and it'll still work, i.e. "you could verify it against LV's centralized product database".
The "killer app" for blockchain technology is a currency.