[xxs]

One note on high quality and carbon Japanese knives - they are way harder to sharpen, also usually come with 17 degrees apex.

Higher HRC would retain the sharp edge for longer, of course - but again much harder (literally) to sharp them.

[pa7ch]

Its my understanding of knife sharpening that carbon steel is easier to sharpen then stainless and that softer steels are more difficult then high hrc steel due to burr removal.

[Hikikomori]

VG10 in Tojiro DP is stainless steel, and even stainless goes up to 64+ HRC.

[rcpt]

I think a lot of German knives are moving to the same angle now