The main point of attributes is to add metadata to code that is easily parseable and can think for itself when you ask for it. Up to now most devs were probably doing this using the PHP docblock thing - those double star multi-line comments. We'd fill them with @tags and then parse that data with Reflection and probably some regular expressions to make any sense of the blob of text.
For a long time now, and like pretty much every other PHP dev out there, at some point I invented my own Object wrapper around arrays to give them nice OOP interfaces. I am a low level person so implementing my own wrappers is far more entertaining to me than just using one of the 34859 that already exist. Mine ended up in a library called Nether\Object that provides a few utilities for things I found myself doing too often making arrays into objects and maybe even back again.
The class in question though Nether\Object\Datastore is
really just a fancy wrapper to handle arrays without having [...]
It may not be believable considering how often even to this day
plain-text passwords get leaked, but the history of the password hash is
a long one. Way back when I was just starting web dev 22 some years
ago, the common practice was when a user creates an account you hash
their password and store that value. Then every time they log in you
take what they give you, hash it, see if the hash matched what you
stored.