Why doesnt '"Uninstall" uninstall directly ?

Welcome to tenforums.

You've not said what you're right clicking or provided a screenshot. I will assume you're referring to the Start Menu.

Actually there are two basic cases.
a. Uninstalling UWP apps (Store apps)
b. Uninstalling traditional desktop apps (exe/dll model).

For reference:
Uninstall Apps in Windows 10
You may find something in the many comments following of interest.
(I have a query about Option 1 step 4 pending having just looked at it)

a. These are handled differently.
b. I think this may be what you're referring to. You've not been specific.

The uninstaller's nature and location is particular to the author. There are at least a couple of different methods adopted. Desktop programs come from many sources over a long history, so don't follow on simple consistent model. Thus it is harder (relatively) to locate the uninstaller.

The old Control Panel approach, part of Windows for many years, is one that I suppose would be difficult (and unnecessary) to replicate reliably. I can only guess that this is so.

Personally I don't use Win 10's start menu- most of my installed programs simply don't appear in it. (I have a large start menu organised into folders).

Instead I use Open Shell (free).
In some cases that includes a link to the program's uninstaller. Whether that's present depends on how the author configured the installer for their program. That's one way to start the uninstallation directly.

Where desktop programs don't include a link to their uninstaller in the start menu I could of course go to Settings, Apps & Features, and uninstall from there.

My normal practice is to use Geek Uninstaller - one of the various 3rd party uninstallers that runs a scan after the normal uninstaller has been run to pick up leftovers (how clean an uninstallation is depends on how the author configured their uninstall sequence).