> I wonder how much of its victory was because it was basically free
Ethernet hubs were much cheaper than anything else. This was the big win. At that point, the only question was TCP/IP or IPX/SPX (Novell).
You could use Ethernet to hook a couple computers in a room together directly and it worked (mostly). Every other technology required some expensive thing to sit in the middle and direct it all.
Then, when you needed to connect a couple rooms together, you could throw a cable over a wall and hook them together.
Finally, when you got tired of debugging the inevitable continuous failures due to the "idiots in that one room", you threw an Ethernet hub into the mix to hook the rooms together. This was a bit more expensive, but still not as expensive as the idiotic middlebox for the other technologies. And the improvement in reliability and debugging was palpable enough that your boss didn't give you too much static. This was THE big win that other technologies couldn't deal with.
Finally, when you had enough computers that even hubs just weren't cutting it, you bought an Ethernet switch. Yeah, that Ethernet switch was about as expensive as the middlebox from all the other technolgies. However, by now, Moore's Law had been running for a few years so an Ethernet switch was simply expensive rather than outrageous. And you had all this installed Ethernet kit, so your sure as hell weren't going to rip it all out.
At this point, the installed base made sure that Ethernet was going to win.