I know you never said it was, but you have mentioned straight RAID as a redundancy solution before and I was just echoing that RAID0 isn't. It's one of the earliest implementations of RAID.
And no, as I continue to say, RAID is fundamentally different than ZFS. I'll keep hammering away at this until you get it. There are no checksums in RAID. At all. On any level. That means a file that's copied can get corrupted, though it's rare. However, rare does not mean never happens. This does happen. The other major issue that all RAID arrays have is what happens if your array goes down in the middle of a massive write. The chances of you losing that data are pretty much assured. However, there's now a fantastic chance that you've corrupted the index. That just lost you every last file on the array and while it's recoverable unless you do a lot of defragmentation (which raises the risk of this happening, oh the irony) then there's a good chance what limited file you recover are going to have some level of corruption.
ZFS has built-in checksums. That means on every read and every write a quick checksum is made to the file to make sure it's not been corrupted somewhere along the way due to basic software errors. Then it uses copy-on-write protection which means that if you were to lose power mid-write the worst that would happen is whatever data you were writing is now lost. However, any data on the zpool form before that is perfectly safe with 0% chance of corruption.
As for performance, it doesn't actually take a lot of processing power to do a ZFS RAIDZ zpool. The big requirement is RAM, which is why a lot of people just skip it and use SSDs as cache disks. However, if you do that, a RAIDZ1 zpool is actually pretty close to a RAID5 array in terms of speed, though not quite as fast as RAID10 or RAID0.
So while some of the things they will do for you are the same, when it comes to reliability ZFS has a near 0% chance of failure over it's entire lifetime where a RAID system will die at some point. It's why if you're doing it seriously you always have at least two independent RAID servers so that when one array dies (and it will) you have the other as the fall-back. ZFS eliminates the need for that second array as a redundancy solution. At least, from any system-level issues.
Neither system touches human-level stupidity. Oh, wait, ZFS does. It has versioning built in to the filesystem, similar to Time Machine and RSYNC, that allows it to take snapshots of any changes at a bit level automatically and roll them back as necessary. Which, oddly, saves you form stupid user errors as well.
Which RAID doesn't do in any circumstances at any RAID level.
So the benefits of RAID over ZFS: RAID is a little faster and is less hardware intensive. The benefits of ZFS over RAID: ZFS has none of the inherent stability issues and is significantly less likely to suffer from any level of data lose.
By the way, to everyone else, I know it seems like this is horribly off topic but hardware isn't the only thing that effects reliability. The circumstances in which a drive is used make a world of difference.