Balanced differential inputs and outputs reject common mode noise, which is why they are essential for long cable runs and microphone leads, among other things that benefit from such an interface.

The actual ADC and DAC chips, or codecs, are usually specced just fine in even consumer on-board audio devices.

Hifi audiophiles are notoriously superstitious, and as long as RCA coax is the connection standard, my eyes continue to roll about their DAC nonsense, but you should pay attention to professional audio as this is where you can hear audible differences. Preamplifier stages and voltage amplification in general have a lot of nuance and analog circuit know-how inside. Removing the codecs from the inside of an electrically noisy computer is the beginning of starting to care about audio signal quality. Power filtration is another major concern for noise. Latency is a factor of buffer size which is both necessarily low when overdubbing recording while monitoring, and yet paradoxically allows for smoother glitch free audio as the buffer size is increased, largely a function that is CPU bound. No one talks about DMA controllers or the data bus employed, often USB, another factor that can affect audio independent of which audio interface or soundcard is employed. Some play nicely, some don't.

My advice is to delve into the world of professional audio, as this is real. Hi-fi often entails gullibility and snake oil in the sales chain.