Yeah, it pretty much was. Counter-Strike and the endless repackaging of SKUs is largely the only reason Valve’s still around.
half-life 2’s deathmatch mode sucked (in my opinion) and half-life 1 didn’t have multiplayer(i could be wrong, but i don’t think it shipped with multiplayer) until someone made counterstrike as a mod for it
It shipped with multiplayer, just it was pretty crappy and had screwed netcode, so no one cared about it compared to QuakeWorld/Quake2.