It's probably been said a hundred times in this thread but I don't have the time to follow it from the start.
I'm not being sarcastic here and I am pretty sure that by "best" you mean best for an EDC folder.
An analogy would be "What's the best plastic ?"
Please don't take it as an insult, but that's not really a useful question.
There are so many variables that change everything such as heat treatment, grind, geometry (as in how thin it gets or blade shape itself), us how, why, and where you will use it most, that the "best" steel becomes entirely dependent on those specifics.
For me the most important tasks are cutting food, opening clamshell packaging, cutting cordage and lines, cutting cloth (labels and threads in both kid's and adult's clothing), marking notches in materials when measuring, neatly cutting out parts from paper (licenses, excess paper on printed shipping labels), opening various safety sealed items everything from aquarium food to over the counter meds....
Basically everything except letters and cardboard.
For opening letters and cutting up all types of cardboard I like S110V.
For average day not being out on the water or on the beach I like CPM-20CV (close enough to M390 that I consider them largely interchangeable), and for days when water or the ocean or beaches are part of the day I like Nitro-V (actually SM-100, I but SM-100 is really hard to find and not technically steel).
It's available, it's affordable, it's easy to work. It's extremely tough and can be ground super thin with great stability. That means it will cut well even when the edge is dull. It's stainless enough for my neck of the swamp. Because I like high sharpness in my knives, and am happy to sharpen and hone periodically, AEB-L is a clear winner for me.
It is everything I love about AEB-L with a few adjustments. It is not quite as tough on paper, but it's still more than tough enough. So no lost points there. It takes almost as sharp an edge, but not quite. However, it holds working sharpness better somehow, and though it is not supposed to be as tough as AEB-L, I always find in practice it seems more so, if not at least on par. Edges never break, they roll, and even with all kinds of light deflecting off the apex, it still cuts aggressively. I love it. It is a winner.
Both of these steels can do, in my opinion, anything. Choppers, small knives, kitchen cutlery, you name it.
I don't know of another steel that even comes close for me. I love 15N20. I love 1084. But the lack of stainlessness, though not a problem per se, is not what I would make for myself in most knives, except maybe kitchen cutlery. I am doing a run of MagnaCut soon, and perhaps it will make the list. I am betting it will.