OpenBSD for 1.5 Years: Confessions of a Linux Heretic
youtube.com
youtube.com
Slackware used to be like that. I haven't used Slackware for quite a few years now, so things may have changed.
Linux tried the same approach, but it had a severe impact upon Linux performance. So "hyperthreading" got enabled by default again.
* https://mail-archive.com/source-changes@openbsd.org/msg99141...
* https://theregister.com/2018/11/20/linux_kernel_spectre_v2_p...