Slip joints, a subject dear to my heart.
As a bonified old fart, I use one, just as I've used one the whole of my long life. I still have all my fingers, have just one scar when I made a mistake when I was a kid and paid for it with a little blood. Never made that mistake again.
Most slip joint patterns came about in a time when men didn't as a rule work in office cubicles. The pocket knife they carried often were developed for their trade. Cowboys and ranch workers developed the three bladed stockman for the much varried and different jobs, including the castration of the cattle. A trapper doing a lot of skinning used, of course, the trapper. Sailors had rigging knives with sheep foot blade and marlin spike. The office types had the small two blade pen knives and the landed gentry that had most other people do their work for them, used sometimes very elaborate lobster patterns with pipe reamers, nail files, little scissors, and even a cutting blade or two tossed in there. Kind of like the modern Victorinox executive pattern, but with very nice pearl or abalone scales.
In my own mostly blue color life, I've worked construction and in the machine shop arena. A nice sharp pocket knife was needed on sometimes an hourly basis. Cutting filthy steel dust covered tape holding a bundle of round stock for the lathe, Opening taped shut cardboard boxes of parts to be modified on the mill, cutting tar covered marline running a line between survey stakes, working in the garden with my better half cutting twine for the tomato plant stakes, and camping with the family and teaching the kids and much later the grandkids, camp crafts like making a one match fire and a perfect hot dog stick that holds two hot dogs on a fork. They all still have their fingers.
I tried carrying a knife with a single looking blade, once. About 9 times out of ten I found the large single blade and no choice of other blades much too limiting. It was either too long and awkward, or too wide, or it was a job that was going to totally mess up the blade. I grew up liking having multiple blades in one pocket size package. It was all about versatility. Choice of having two or three different blade shapes with different edge profiles was nice and even habit forming. The main clip was kept vey sharp for clean cuts on fish and game, the sheep foot was somewhat sharp for opening boxes and packages, and the spey blade, since I was not doing any castration on creatures, was dull and my scraping, poking, and whatever blade that I didn't worry about messing up the edge.
Contrary to popular opinion, they had locking blade knives in the old days. John Wilkes Booth had a folding dagger with a locking blade in his pocket when he was killed at Garrets Barn in 1865. They just never were popular with the working masses. Cowboys, farmers, sailors, freight wagon drivers, store keeps, livery stable workers, and the rest of the working masses used a simple slip joint. In the mid 1800's the humble Barlow knife pattern was the most popular knife shipped west to trading posts, general stores. The John Russell company made tons to them and with simple saw cut bone scales and two different blades, it was a number one choice of lots of people who worked hard for a living. In truth, the Barlow's clip point and small pointy pen blade gave a lot of versatility in a small package.
Go ahead and drop the Buck in your pocket and use the living hell out of it. You'll come around in the end.