[1] https://man.netbsd.org/raid.4
I first ran across the "RAID-5 is dead" 'meme' almost twenty years ago, with concerns that when drives reached >2TB you get higher chances of failed rebuilds due to BER / UER rates:
* https://www.zdnet.com/article/why-raid-5-stops-working-in-20...
See also 2013 follow-up:
* https://man.netbsd.org/zfs.8
FreeBSD's graid(8) does appear to RAID6:
It's why it doesn't really bother me when, say, the Linux kernel drops hardware support for older architectures.
Much respect to the NetBSD and port maintainers.