This is rasbperry pi 1 the post is about. It's not a super computer. Running updates and unpacking archives chokes the SD and CPU on official raspbian with ext4. It only has 512MB of memory, so ZFS would be killing it.
Yeah, the pi 1 is really slow for a lot of things these days. While the post mentioned they started this on a pi 1B+, everything else is about running things on model 3 units.
Yes, regardless whether RPI1 or 3. These boards are quite weak. I wouldn't want file system to one of the biggest bottlenecks on a running system. I had BRTFS on rpi3 before and don't recommend it. Both FS are CoW.
No it's not; you still get detection of errors (just without correction), compression, arbitrary filesystems in a single pool, and snapshots. ZFS is great regardless of RAID.
Exactly, that's why my offline/off-site backups are all zfs, well and encryption and compression (zstd-19), at least i know that something is damaged an can (or not) get it from another backup.
You can always set copies=2 to work around block-level failures on important datasets.
Beyond that, you still get all the other ZFS goodness for management, snapshots, compression, zvols, error detection, send/recv, and so forth. Best of all, you can always throw another disk at it and convert to a mirror if the situation changes.
I suppose it might look pointless if you need to jump through the hoops to get it running. In FreeBSD ZFS is properly integrated, and ZFS is a perfectly fine default root filesystem; there's no reason not to use it, except eg very memory-constrained virtual machines.
