The general rule is what @Valynor stated. The super steels that people love are generally harder to sharpen because of the higher percentage of the harder carbides in them. This is not directly tied to hardness. There is another parameter called machineability that is more closely tied to ease of sharpening. So you really need to look at the properties of the steel in total to figure it out. There are some steels that harden to ,say, 61, that can be easier to sharpen than those at 59.
There are several high carbon steels that are easy to sharpen, but you lose edge retention, rust resistance and in many cases hardness.
Here is an article that is sort of an overview:
Here is another. It is long and detailed, but if you get through it, you can answer your own question. If you want to just see what he says about ease of sharpening, scroll down a long way, almost to the end.
But, if you get the proper sharpening equipment, even the super steel (high hardness, high carbide, high chromium Stainless) steels are not that difficult to sharpen. It is only a matter of degrees.
So it is a tradeoff, like so much in life. You need to pick your compromises. Certainly hardness is a consideration, but not the only one. Sorry about the length of this, but unfortunately, what seems to be a simple question, just does not have a simple answer.