20 years back I remember chatting to a sysadmin over beer and the conversation included "Linux mostly does either whatever Solaris does or whatever BSD does, you just have to check which it is before trying to write anything."
(this was not a complaint, we were both veterans of the "How Many UNICES?!?!?!" era)
I've often thought Sun and Solaris also won, since so much of Linux is open source reimaginings of what Solaris had in the mid-late 90s, essentially a few year head start on Linux (which i used in the early 90s and still do, but along with Solaris back then, and NeXTstep).