OpenBSD and Debian are really the only systems I use and trust today. I'm sure there are some other 'old-school' open source operating systems out there that are just as useful. But these two have been great over the last 25 years.
Isn’t https://en.m.wikipedia.org/wiki/UNIX_System_Laboratories,_In.... the answer?
Linux was completely safe, BSDs were a risk, the choice was easy.
USL / AT&T basically kneecapped the bsds.