I am not a purist when it comes to knife steel(s).
Custom knife makers have done a great deal to popularize some very exotic steels. Many of these steel alloys have their origins in the aerospace industry. Others were spawned by the need for ultrasmooth bearings for hard-drive data storage devices.
Personally, I think any steel that can be hardened to 55 Rockwell C makes a fine knife. In a pinch, I would even say 40 Rockwell C which is spring/high-strength bolt territory. Maximum hardness in most steel alloys is dominated by the the carbon content.
Most other alloying elements are added to steel to increase depth of hardening. That is, so thick sections of steel reach full hardness through their entire thickness. Knives are rarely thick enough to require anything beyond the normal amount of manganese in common "carbon steels" to reach full hardness. That means that any steel with more than 0.50% carbon will reach the ERJ approved level of hardness.
So there you have it, any grade of steel with 0.50%-through-1.5% carbon will get it done.
Most of what I cut with a knife is not very challenging. Cords, green branches, weeds, food and the like. When my knife gets dull I sharpen it. Exotic alloys are not needed for what I do. I don't need "massive carbides" or "excellent hardness at 1400F" to cut cabbages.
I even find the use of stainless steel to be a bit over-the-top most of the time. I carry a knife in stainless because it was the least expensive knife I could find. Quantity has a quality of its own.
I prefer a straight edge to a serrated edge.
And even though it is heresy in some circles, much of my finer cutting work (like grafting) is done with a work knife with disposable blades.