The Shannon-Nyquist theorem doesn't assume or apply just to sines (that's a gross mischaracterization of the proof and it's implications). It assumes ideal samplers and reconstruction filters can exist, which they can't.

In the real world, ADCs and DACs' inherent filtering, noise, and distortion characteristics are quantifiably superior to any analog storage media and reproduction system.

Records don't have infinite bandwidth either. I'd actually love to see a comparison of vinyl vs digital reproducing a triangle wave, it would be a lot more illuminating than blindly quoting Shannon Nyquist.