1) The "Old Steels" like 1095/5160, 440A/440C and 420HC still work just fine.
2) Not everyone "needs" or wants a 'super steel".
3) Not everyone has diamond plates or a SiC stone.
4) A lot of folks place "ease of sharpening in the field" at the top of their "must have's"
Personally, I don't "need" a knife that will hold a working edge for a week or more, that takes an hour or more to sharpen when (not "if") it gets dull. All knives eventually get dull and need sharpened. A "lower"/"obsolete" steel may only hold its working edge for a couple days, but only takes a couple swipes on the stone, strop, or steel to restore the edge. The "softer" older/"obsolete" steel can also be sharpened with a river rock if afield for an extended period, and you lost or"forgot" a sharpening stone. Rolled edges are a heck of a lot easier and faster to fix than a "harder" chipped blade, too.
In 60 years, I've never "needed" a blade over 57 to 59 on the Rockwell C scale.
Do I have harder? Yes. Up to 61 or 62, I believe; D2, CPM154, and S30V by Buck. They don't get as much use as my 1095, 440A, and 420HC knives of the same style/pattern, though.
5) Believe it or not, Most people (including "knife knuts") don't know, and don't care what the differences are between the various steels used for blades.