Blockchain is another word for Merkel Tree. ZFS uses Merkel Trees, so it is a blockchain implementation.
Is it better than NTFS or EXT4? Most definitely yes. Does it enable you to do anything that isn't possible on NTFS or EXT4? Maybe from a systems administration point of view, but not in terms of the applications you can run on it.
APFS uses Merkel Trees. It has been around since iOS 10.2, about 4 years ago. So your iPhone runs on a blockchain. Did you notice any difference to your phone when you upgraded to iOS 10.2? A few people noticed that the upgrade process failed and they ended up with a bricked phone, which obviously isn't good. Most people just noticed some new emojis, which has nothing to do with APFS or blockchains.