It really isn't. Onboard sound is indeed "good enough," but that's not mutually exclusive with sound cards being worth it if you can afford them. Onboard sound no longer sucks so bad that you can notice the flaws without any basis of comparison, but when you DO have one, the benefits of the more expensive stuff are immediately apparent. Much richer bass, and cranking the volume doesn't flatten the sound or cause crackling. I'm using onboard sound now, because I can't afford an upgrade, but I definitely notice what I'm missing from when I did have a real soundcard. It's not nearly as important with gaming, but if you're listening to music, you can only miss the difference if you're completely tin-eared.