And if you want to play sound, you buy a sound card. Computers integrate components that approximately everybody needs. Hardware storage for keys is just the latest example

The main component of a yubikey is that it requires a human presence to hit the button and access the secret.

Do new computers have such a button? I've failed to locate it.

Touch is one way of demonstrating proof of presence. Biometric is another. Pin is a third. Yubikeys typically support touch or pin. Windows Hello (which is TPM based) supports bio or pin.