Great post and perfectly true. In the end, it all comes down to personal taste. I've often said that knives are like ice cream. You can walk into t a 31 flavor ice cream place and 10 people will order 10 different things. One guy may like plain old vanilla while the next guy gets mint chocolate chip. It's all in what you like. And what stage your life is in. I've carried everything from a Case peanut to a large Eye-Brand sodbuster, and liked them all at that time. All depended on what I was doing. For a very large chunk of my life I carried a three blade stickman almost 4 inches in closed length. Now I'm happy with a peanut or Opinel. And more and more, I've become interested in friction folders as an edc.
Do we need multiblade knives? No, not really. It all depends on where you grew up. Being a post WW2 kid, I grew up with men who all carried some sort of two blade jack. Somebody growing up in Wyoming cattle country may lean towards a stockman, while someone from Sardinia, Spain, or rural France, may go for a simple one blade friction folder. They all do the exact same thing for the owner; cut something that needs to be cut. A cowboy cutting something, and a shepherd on the arid hills of Northern Spain, all use a knife for the same thing.
Personal preference, individual taste, all makes us who we are, and what we like. One blade, two blades, three, all the same. Myself, I have a hard time choosing between chocoalte chip and rocky road.
Carl.