For a folder, D2 is a strong choice if you accept two things: it needs drying after wet work, and it wants diamond or ceramic abrasives. In exchange you get edge retention well above budget stainless at a price well below powder steel, which is why D2 has stayed a folder staple for decades.
A pocket knife spends its life cutting tape, cardboard, cordage and food, all of which are abrasive in different ways. D2's high carbide volume is exactly the right answer to abrasion, and at 58 to 62 HRC it stays sharp through a lot of it.
The moderate toughness that limits D2 in a chopper matters less in a folder, because a three-inch blade is not being batoned. The failure mode you might see is a chipped tip if you pry, which is a user problem more than a steel one.
It is semi-stainless. Around 12% chromium sounds like plenty until you know most of it is bound into carbides. In a pocket, against a damp thigh, D2 will spot if you never wipe it. A wipe and an occasional drop of oil on the blade solves it entirely.
It is slow on a stone. If your sharpening kit is a basic aluminum-oxide stone, you will find D2 frustrating. A cheap diamond plate transforms the experience.
Against 8Cr13MoV, D2 holds an edge considerably longer and is harder to sharpen. Against 14C28N, D2 wins on retention and loses on toughness and corrosion resistance.
Against S35VN, D2 gives up refinement and costs a good deal less. For a working folder that is a reasonable trade.
The full reference entry, with the published composition and hardness range and every listing we carry in it, is D2 Tool Steel in the Steel Lab.