I can't hear anything above 20 kHz, and neither can most people. CD audio is passed through a 20 kHz lowpass filter. It is then sampled at 44 kHz. Due to the Nyquist Shannon Spamling Theorum, when sound is digitally sampled at just above twice the rate of the source audio, converting it back to analog perfectly reproduces the original waveform. And I do mean perfectly. The exact same waveform. (The extra 4 kHz is to prevent artifacts in frequencies very close to 20 kHz.)
Therefore CD audio is perfect unless you think you can hear above 20 kHz. (Spoiler: you can't) There are a few good YouTube videos on this topic, and the best ones are very mathy.
Is there something I'm missing? Do I need to educate myself some more?