You can use the mouse to hover over entries while keeping Cmd held down, and q will quit whatever your mouse is over.

Useful for "I just want to quit every app": just move the mouse left and right over the icons while pressing Q repeatedly until everything's dead.

Command+q is the standard to quit in all well-behaving macOS apps. No need for tab.

Obviously. This lets you quit an app without switching to it or right clicking it on the dock -> quit.