[unboxed_type]

>But of course, if this is the case, then it begs the >question of why a blockchain is even needed. Just use a >shared database.

Two issues regarding your second observation.

1) A change that requires a consensus among some non-tiny group of participants is not trivial thing to accomplish in practice. You will have to wait before every one from a group of N (say, 20) representatives will agree with your change.

2) Why a blockchain is needed? Because no other "shared database" provides the same trust model which is "everyone trusts no one". Every other database "security model" in existence assumes that every admin trusts every other admin. If it is not so, then things quickly become complicated and impractical.

[routerman]

Good points. From a consumer's perspective, I do hope that they would eventually choose to build on a public blockchain. The fact that consensus is provided by miners worldwide (or stakers in PoS chains) instead of a couple of diamond-related companies means that there is one less thing for me trust.