The key advantage of balanced signal connections is that the impedance on the + and - sides are close to identical. Given that, then the noise that is picked up on the two signal lines ought to also be close to identical. The signal is derived by essentially subtracting the two signals, so if the noise is close to identical, it "close to disappears".

If as stated above, the signal run is short or otherwise unlikely to have noise issues, there will be no problem.

In an unbalanced connection the - or reference or ground is grounded and has as close as possible to zero impedance to ground, so noise picked up on the + or signal wire will be "subtracted" from an extremely small induced noise on the ground line, leaving most of the induced noise intact.

This is why balanced is king for long runs and places with a lot of power and switching noise in nearby wires along the way.