It makes it way faster when you can right click, hold, and release on the item in one smooth motion. I believe most pro software is like this, it's hardly breaking convention.
I understand why some people like it, and yes a lot of software does that as well, but in my case sometimes I accidentally end up pressing some menu option because I'm not perfectly steady. That's why I'd like it to be an option.
Did you get those the right way round? All other software I tested opens menus on button press. IIRC, Blender defaults to opening menus on button release, adding unnecessary latency and making it feel slow. You can change it, but you have to go through the whole Keymap Preferences and find every menu and change it individually, so it's annoying.
On my Windows machine, all the "native" software like the file explorer and so on, opens when releasing the right click. Blender 3.6 opens as soon as you press the right click (allowing you to "drag" the cursor to the menu option and releasing it there)
That's the traditional Mac way. e.g. historically you would "pull down" on the menu bar at the top of the screen. You would click and hold, and slide the mouse down, releasing the button to choose an item. If you were to just click on a menu, it would quickly open and close again. I want to say it's typical for Linux desktop environments to open contest menus on mouse down, as well, but don't recall offhand.
Blender dates back to 1994, when many modern conventions weren't really a thing yet (Windows 95 didn't even exist)...and they have put a lot of time into modernizations in recent years. Back when I was dabbling in Blender, in the early 2000s, Ctrl+S was the keyboard shortcut for "erase everything and create a new scene."
I think it's UX that commonly works differently in consumer software vs pro software. I think parent is talking about professional software.
Pro software made for speed and efficiency, you usually want to be able to do things quickly, even if sometimes people not used to the software might screw up. Holding right-click, selecting menu item and releasing I think is one of those things.
In consumer software, users would be confused because maybe they long-press the right-click, drag the mouse a little while holding down then releasing, and the menu would just appear and disappear. Confusing UX for most users, I bet.
Maybe it depends on the platform? For me, on Windows with Chrome, it only opens the context menu once you've stopped holding down the button. In Blender (on Windows), the menu opens as soon as you hold the button.
I wish they had at least a setting to change that.