ZFS doesn’t have fsck because it already does the equivalent during import, reads and scrubs. Since it’s CoW and transaction based, it can rollback to a good state after power loss. So not only does it automatically check and fix things, it’s less likely to have a problem from power loss in the first place. I’ve used it on a home NAS for 10 years, survived many power outages without a UPS. Of course things can go terribly wrong and you end up with an unrecoverable dataset, and a UPS isn’t a bad idea for any computer if you want reliability.

Totally agree about mainline kernel inclusion, just makes everything easier and ZFS will always be a weird add-on in Linux.