The philosophy was that anything visible in a context menu should also be in the app-wide menu bar. Instead of bring up a context menu and click Copy, you would find the Copy menu item in the menu bar. Therefore such menu items can be assigned any keyboard shortcut by the user.
I quote from Apple https://developer.apple.com/design/human-interface-guideline...:
> Always make context menu items available in the main interface, too. […] In macOS, an app’s menu bar menus list all the app’s commands, including those in various context menus.
Therefore one can rightly conclude that there is no need for a key to bring up a context menu.
In this case it's not a context menu, it's just a menu. User experience is degraded, see GP's case. There is an expectation and a common paradigm which is intentionally ignored because the OS developers thought they knew better than the users.
This reminds me of frequent conversations with other developers when presented with a bug report. "That's not a bug, it's working as intended." The intention is wrong, then -- the bug is in the design, not the code, but it's still a bug.