The ligature matters - a lot, particularly for the player who is always trying to extract the most sound from the horn. You don't have to understand why. All you have to do is find a great ligature for you, then try another one that stifles the sound. I did this exact same thing last week - I had bought a new Rovner for metal tenor and was using it at a rehearsal when I had trouble finding a reed that would speak (using my known good reeds from the last gig). On a whim, I dug out my previous Rovner and put it on - bingo. Night and day! Obviously I have used many kinds of ligatures over six decades. Now I use a different Rovner on each horn depending on the needs of that horn and mouthpiece. That is, except soprano where I'm using a standard HR-type lig. My problem with Rovner is just when I find something that works, they discontinue it and I have to start over. I guess that's the brainchild of their marketing director - get 'em hooked then change everything so they have to buy more ligs.
If you play the stuffy, quiet way with that popular dead sound, then sure, what the hell? No ligature can change that, and you don't want the change to start with. So for you, the ligature doesn't matter. For the higher-performance player who relies on a fat sound, the lig can matter.