(Photo: Public Domain, via Atlas Obscura)

I think I get the basic concepts of what blockchain is and the technology behind it:

A ledger (database of transactions) that is distributed (a bunch of us in different locations have it), immutable (once some data is added it can't be removed), and encrypted (secure).

• Given that it's a ledger, you can look back at what has happened before.
• Given that it's distributed, no one person/company controls it.
• Given that it's immutable, you can't go back and change past records.
• Given that it's encrypted, no one can steal the stuff stored unless they have the keys to that specific data.

Despite all those things, it still seems like it's just a database with some simple problems:

• People stink at data entry: Do techies really think that everyone is going to constantly track everything they do, and make sure that someone can go back and see exactly when something happened?
• Theoretical security isn't the same as actual security: the transactions are supposedly private, but the entering of that data and reading it back certainly wouldn't be for many users. People will still use bad passwords.
• It's expensive: a full public ledger would be huge, even if it's distributed, it has to be stored somewhere and hard drives ain't free. Not to mention, the energy usage is massive.
• Technology changes, and what works now won't always work: What happens if the system used to enter the data is incompatible with the system used to read it back?

Why are so many people talking about it as a cure-all? What am I missing? Please help me out in the comments below.