Question about RFI in AC circuits

[Jay112]

Can anyone please tell me what the following paragraph means? It's from a digikey description of a zero voltage switch:
"Zero-Crossing Detector - Synchronizes the output pulses of the circuit at the time when the AC cycle is at zero voltage point; thereby eliminating radio-frequency interference (RFI) when used with resistive loads."

How does synchronizing the output at the time when AC is at zero voltage eliminate RFI? I just want to learn.

[Audioguru]

The voltage of AC swings to a positive peak then drops through 0V then goes to a negative peak then rises through 0V to go positive again, over and over. If a switch is activated at a voltage peak then the high voltage causes interference. But if the switch is activated when the voltage is 0V then there is no interference. The AC 0V is detected by a zero-crossing circuit.

[Tomorokoshi]

Another way to think about it:
Let's say my Triac gets turned on at the peak of the AC cycle. We are then switching the load circuit from 0V to 170V in the turn-on time of the Triac. Although it's a resistive load, there is some inductance and capacitance in the line. The "step" function of the Triac turning on looks like a square wave edge, which will look like a blast of energy at a wide frequency range, particularly across the AM band.

By starting at the zero-cross, there is no meaningful sudden voltage switching - it just happens to have a higher load on that next cycle.

Turning off at the zero-cross is also important.