The web run on Linux like most FANG servers do, so it makes sense with the $$$ / people / R&D that this OS is faster. A conservative number would be that 99.9% of the web runs on Linux and it's probably much higher.
At the scale of Google / MS / Amazon / Apple if servers would run faster of BSD* they would use it. We're talking about 10's millions of servers here.
Based on that logic, Windows is the superior operating system and always has been, because it's always been used by more people on their desktop than anything else.
There are a lot more factors involved in OS choice that could drive popularity other than the speed of the network stack. And BTW, Hotmail runs on BSD. MacOS is a fork of BSD. And Yahoo ran on BSD (and may still).
At the scale of Google / MS / Amazon / Apple if servers would run faster of BSD* they would use it. We're talking about 10's millions of servers here.
https://www.phoronix.com/review/bsd-linux-eo2021/7
It gives you a pretty clear picture.