Consider it the other way around
There are 10's of thousands of copies out there of the blockchain.
It's like running RAID1 with over 10,000 mirrors
Performance is important in core (well I'd say it's the most important thing, since I run a pool)
It's not hard to get that data back if anything goes wrong, but something going wrong should be rare not common.
The only file on your node that is critical and possibly irreplaceable is the wallet file, if you have a wallet on the node.