It would be interesting to know how much progress has been made in steels and heat treatments over the last few decades. Some of the ancients used not only iron and bronze for weaponry, but put edges on wood. Many knives today are fine for defense, cutting boxes, cords and so forth, but they're not good for carving figures out of wood or doing intricate work that a hobbiest might enjoy. Some knives are made for hunting, some for throwing; and some knives can do prying and hacking.
Softer steels may be better where corrosion is a problem or if the blade needs to be tough and not something that can fracture if hit sharply. (Then, not only steels, but the grind and geometry of the blades come into consideration.)
I don't know how long stainless steels have been viable material for blades, but I remember a lot of really bad stuff decades ago. (A friend had a hardware store and I used to look through his knives occasionally. His Case knives seemed to be about the best.) In my younger years I had both a Boy Scout knife and a Barlow folder. The Boy Scout knife rusted quickly despite my wiping it down with an oily rag. I don't know what they're making Boy Scout knives out of today, but I've wondered.
