There is no keyboard shortcut I know of and after checking Google forums, neither does anyone else.

You could use the extension Close Inactive Tabs instead - This adds a button which closes all other tabs except the active one.

Hi

Welcome to the Microsoft community.

In Microsoft Edge, you can use the following shortcuts to accomplish your needs:

Close all tabs: You can use Ctrl + Shift + W to close the current window, which will close all tabs. Additionally, you can turn off the option in the settings that requires confirmation to close all tabs.

edge://settings/accessibility

Open a new tab: You can use Ctrl + T to open a new tab and switch to it.

Resize Microsoft Edge to a fixed window size: For resizing Microsoft Edge to a fixed window size, there is currently no direct shortcut available. You need to manually adjust the window size.

Best regards

Tommy Jin | Microsoft Community Support Specialist

Generally on Mac, Cmd ⌘ N will give you a new Window or full document, Cmd ⌘ T will give you a new Tab.
Cmd ⌘ W will close the last - either - tab or window, depending on whether your document is already tabbed, or a single window.

If you need to find any key command attached to an action, then in most apps you can search the Help menu.
If you run an app fullscreen, you won't see the menu bar until you hold your cursor close to the top of the screen.
As you float your cursor over each item in the help menu's found list, it will pop out the associated menu item with a big slow-moving arrow pointing right at it.

Sometimes, a menu item has new options if you hold the Opt ⌥ [Alt] key at the same time…

You can do this whilst the menu search is showing you a menu, just to see. You can then either directly mouse over & click the highlighted item, or remember its key command for later.

It seems the method you describe is currently the only true way of doing this. However, if you press the back key, it will close the current tab once you've gone back through the history of THAT tab. So if you open up lots of tabs but then close each one after reading, this is a very quick method for you (1 click). If you do extensive browsing in each tab, it's not as good but still easy in that you just press one button

There are many other browsers out there (Firefox, Dolphin HD / Mini, Boat Browser / Mini, Opera, Maxathon, SkyFire) which are all great applications (as you can tell by their app star ratings), albeit with different levels of integration with you Google account. Several support addons or plugins to provide additional functionality.