Replaceable blade knives
The skill and time required to sharpen dulling knife blades is a trouble too much for most people nowadays. There is a wealth of very reasonably priced new and very sharp blades, most of which keep their edge well. A similar huge range of handles is available to take these blades and store a fresh supply. The increasingly popular snap-off blade can be "resharpened" several times (13 on the 9mm snap-offs).