I think scissors just take a little practice. In 2009-2012 I spent a lot of time at a TT club that was in NYC's Chinatown back then (closed in 2012). One of the guys who worked there was a close friend of mine for years before I ever went there. He and the owner of the club used to build rackets for people and watching them, when they cut with scissors it was so fast and came out so perfect, that I was stunned because I knew I could not do it that well. At a certain point they had me help assembling rackets every so often.
I still can't do it as well or as fast as they did. But, nothing is quicker and my cutting usually comes out fine in my book. Their cutting came out pretty close to perfect. Mine, good enough. I just use regular titanium art scissors that I got at an art supply shop. The most important detail is that they are very sharp. And then, technique-wise, when you cut with a scissor, the most important thing to know is how to avoid the handle as you start the cut....to start from under so the handle is out of the way of the handles of the scissors, and to make small cuts until you are clear of the handle. After you are clear of the handle, the rest is easy until you get to the end where the scissor blades are facing the handle, and then, again, you direct the scissor blades below the handle as you did with the scissor handles at the beginning....and, you make small cuts near the handle.
Done with skill, it works just as well and there is no fuss.
But if someone wants a perfect cut and wants to use different versions of razor/knife cutting, it is fine. With either you can get a good cut. There is an X-Acto Knife with a big handle like a screwdriver that allows you to put more force into the blade than any smaller handle would. There is also an X-Acto blade specifically designed for carving that works better than any other blade I have used. If you are holding something tiny and sharp, it is harder to apply force into the sponge.
With scissors, the more practice you have, the more professional the cut ends up looking. I suppose that would be the case with a razor/knife cut as well. But if it takes me more than 15 seconds to cut each side with a scissor, I would be surprised.
To each, his own.
I am one of those people who feels their racket is not a real racket until it has some dirt, sweat stains and dings to make it look like it has been through some battles. There are others who like their blades to look like it was brand new forever. Either is fine as long as it works for you. There are the Felix Ungers of Table Tennis and the Oscar Madisons.