No, but it's the easiest way for users who don't know exactly what to do, I think.
Edit one line versus right click and add a jar... and figure out what other jars that jar depends on and add them too, etc.. In reality, I almost never edit my build.gradle files once the project is under way. I understand that a GUI is easier but only if it actually IS easier.
Your list misses these for example:
...and includes a whole bunch of stuff you likely don't even need. (like niftyguid) or at the very least won't work without a bunch of other jars, too.
The SDK has built in libraries that bundle things you need together. It saves you from some of this, too. Else if you are not using the SDK then you are better off using an actual build tool rather than hand-cobbling a bunch of jars together manually.