Exactly, plus we could almost certainly make a biodegradable balloon envelope if we really wanted to. The original airships used gas bags essentially made of sausage casing (it’s actually called goldbeater’s skin). If we can make lab grown meat we could probably produce lab grown intestinal membrane.

Fun fact, if the numbers given on wikipedia are to be believed, an average WW1 Zeppelin needed about 80,000 oxen worth of intestine. The USS Shenandoah would have used around 300,000 oxen worth and it got destroyed by some wind.