Your mirrors can be more than 2 wide, you can have automatic hot standbys, you can make each mirror its own zpool so loss of some drives doesn’t lose the entire pool.

Actually losing a mirror vdev doesn’t lose the whole pool anymore for several years now. I’ve recovered data off a zpool where I lost one of three mirrored vdevs. It’s not pretty, but your data is still there. Any files on the missing drives are just 0 bytes.