You are right. I have installed Monterey on my iMac yesterday and gray keyboard shortcuts for available menu items was first of confusing thing I noticed. I assume designer wanted to make it nicer (Why to make the right part of the menu fight the left side, it can be nice and grey, right?). But I, and I believe a bunch of other users, look sometimes only at the right part of the menu to find the keyboard shortcut as it’s faster then reading the very text of the menu I know already and thus I don’t read any more. Simply put, I use shortcuts as a replacement of the icons because it’s just faster.
It was a bad idea to the keyboard shortcut grey because since it’s grey you have to look left at the color of the menu item whether it’s black (so I can use it) or grey (so the item cant’t be used at all).
Going to ask Apple to make the keyboard shortcut darker when the menu item is available.