Whats the point of the Apple File System? What does that mean going forward.
It means a lot. APFS is a modern file system with lots of interesting features that HFS+ either does not have or has obtained through convoluted workarounds. APFS is basically a refactoring of these features and it implements some advances in this area that other, newer file systems have obtained over the years.
I don’t think it will be that much of a deal for the iPhone user. In terms of raw performance, I don’t think you will see any leaps. I do think that you will get quicker and more predictable information about your storage usage though.
On macOS, it has more interesting user features. It has its own snapshotting feature built in that could replace Time Machine. Moreover, you will have more flexibility in terms of disk partitioning and it should also get rid of the separate CoreStorage layer.