> A centralized MySQL database is not a "public ledger" in the same way that a decentralized blockchain is considered a "public ledger."
A public ledger is just that, a public ledger. It need not be distributed nor trustless to be public. The novelty of blockchain is the distributed and trustless, but most applications (as I outlined in the example above) only need to be public.
Trust me, I understand that a database dump is very different from a blockchain ala bitcoin, in exactly the ways you described, but that doesn't mean we need to shove blockchain everywhere.
I concede with this and your earlier point, you don't need a blockchain to build a new banking system. The current banking system is evidence of that: there is no blockchain needed when you ask your bank sends your funds to another bank.
But if you want to build a system that is not wholly dependent on "banks" and centralized actors securing consensus of financial transactions - which is effectively Proof of Authority - you end up having to look at alternative consensus mechanisms like Proof of Work or Proof of Stake.
The same logic applies to something like game assets. People buy and sell game assets already without a blockchain, but they do so only through centralized custodians and intermediaries.
A public ledger is just that, a public ledger. It need not be distributed nor trustless to be public. The novelty of blockchain is the distributed and trustless, but most applications (as I outlined in the example above) only need to be public.
Trust me, I understand that a database dump is very different from a blockchain ala bitcoin, in exactly the ways you described, but that doesn't mean we need to shove blockchain everywhere.