Back of napkin estimates:

For lossless CD-quality audio you need about 160kbyte/s.

So on a gigabit network (125Mbyte/s), you'd need over 99.999% packet loss in order to not keep up.

So they're comparing to an almost completely faulty cable.

I feel like a lot of audiophile stupidity is not understanding scale.

There is a difference between the fancy speaker cables and acceptable cheap ones, but it's so ridiculously minuscule as to be completely inaudible compared to, say, whether or not the listener is wearing socks or not.

The only real difference between the cables will be at frequencies over, say, a GHz. ie RF frequencies 50x higher than cats might be able to hear.

But the audiofool will say, "see, there's a difference - I want my system to sound the best".

And they focus so much on ridiculously overkill cables, amplifiers and stands, yet seem to often ignore room treatment which could really make a difference. It's often massive speakers in horribly reflective minimalistic rooms, driven by amps running at 1% of their power rating.

As someome pointed out, even 99% packet loss on a modern network wont affect the stream. I've actually seen (unfortunely) 100mbit "working" with cat3 (phone) ribbon cable... For short distances (<10m), it wont even reach 10% packet loss. And players buffer. Always.