The difference between ceramics and steel is that steel has a degree of elasticity, which allows it to be stressed without breaking. And there are some steels, along with some grades of iron, that will shatter if misused. Steel tools, such as case-hardened chisels and hammers can and do chip, often sending sharp metal shards flying through the air. Cold-rolled steel, and wrought iron are both relatively soft and mallable.
Generally speaking, the harder the material is, the less elasticity it exhibits. Less elasticity results in brittleness.
Ceramics often have superior properties compared to steel in certain applications. ceramic bearings are tougher, wear longer, and have less friction than do steel bearings. Ceramics are temperature insulators and at one time were seriously looked at for adiabatic, internal-combustion engines (for cars and trucks). The natural insulating characteristics meant that less of the energy derived from burning fuel would be lost as heat, thereby making the engines more efficient. But again, the brittle nature of the material made the ceramics too dificult to be useful. Ceramics tend to have as much as, or greater tensile strength than does steel or iron. However, thermal shock, and the inability to bend creates catastrophic failure of the material, where steel will just bend, and if tempered properly, or not bent to excess, will return to its original shape.
Yes, ceramic knives offer superior sharpness, and edge retention, but have to be used specifically for what they are designed to do. Then again, they don't rust, or add unwanted metallic ions to foods like some steels will (high-carbon steel).
The ideal in steel knives is to produce a metal with good sharpening characteristics, and edge retention, while mainaining enough elasticity to make the blade durable and tough. The softer the steel, the easier it is to sharpen, and the more quickly it will become dull.
Japanese knives tend to be lighter, and rely on better edge shaping to achieve their cutting abilities. German Steels tend to be tougher, and a bit softer. They are much heavier and utilize the weight to help push the knife through the material being cut. Both have advantages and disadvantages. You just have to try a few, and determine which style you like better.
And if you don't mind the work to properly care for them, good old high-carbon steel knives are inexpensive, easy to sharpen to a razor's edge, and last a life-time as well. But they need to be carefull washed, dried, and oiled after every use as they rust very easily.
Hope that helps a bit.
Seeeeeya; Goodweed of the North