This is incorrect. Several posts in this thread conflate balanced inputs and outputs with balanced internal amplifier circuitry.
Balanced inputs and outputs, when designed properly to AES48, have advantages over single ended interconnects even if the underlying amplifier circuitry is not balanced.
Balanced I/O doesn’t use the cable shield as an audio return. This prevents ground current induced hum between different pieces of gear. By being balanced, interference impinging on the cable will be cancelled out by the balanced input circuitry of the receiving piece of gear. Most XLR connectors offer a locking mechanism not present in RCA connectors.
Balanced internal amplification circuitry has additional advantages in that certain types of distortion are cancelled out.
To make things more interesting;
You could have an amplifier with single ended inputs and balanced internal circuitry.
You can also have a situation where a truly balanced amplifier has poor common mode rejection, making it no better than a single ended amplifier in this regard.
As to which works or sounds better, it’s more how these circuits are implemented by the manufacturers than the actual configuration of the gear and weather you use a single ended or XLR connection.
In other words, XLR cables are better. [emoji51]