As well as Larioso’s points, having specific volume changes in place while you compose makes the mixing stage a lot easier (& faster). Using trim to do this as opposed to regular volume automation leaves you fully in control of the fader at all times yet keeps your creative changes in place - keeping everything relative to whatever fader level you choose to have (which often changes a LOT as you progress with a project!)
That’s what I don’t understand about your (Raphie’s) argument about it being ‘redundant clutter’!