There are only two practical lighter than air gases for balloons, dirigibles and blimps

And one of them is Hydrogen and after the German Zeppelin burned up in the U.S. and burned many people up too they stopped using hydrogen for Balloons in general. However, sometimes people use hydrogen in 3rd world Countries for party balloons still and people still die when someone is smoking nearby when they do this. But, for the most part people don't use hydrogen to lift Blimps and dirigibles anymore at the very least.

So now, as helium becomes scarcer and scarcer as years go by likely you will see many less dirigibles, blimps and lighter than air balloons in general everywhere.