Have you ever been using your phone with the volume up, and wanted to turn it down halfway? If you want to turn it down slightly, tap the volume button. If you want to turn it down a little more, tap it a few times.
I have never in my life wanted to turn down the volume part way by holding down the volume button. I’ve never met anyone in my life who turned down the volume this way. Up, maybe. Maybe you want to hear something when your phone volume is off, so you turn it up by holding the volume up button until you can hear it.
When your phone starts playing something in a crowded place and you want to mute it, those two seconds of gradually turning down the volume feel like an eternity.
I hold the volume down button to reduce loud sounds to reasonable levels. Way faster than tapping it 6 times, and if I want a mute I swipe down and mute.
It does turn down pretty quickly on my phone, way shorter than 2 seconds, so this might be a bigger deal on another type of phone.