I have had dozens of people ask me why I have fiddle leaf ficus plants (2-3' ones) when they could not find them anywhere else. For a long time I thought they were just pulling my leg. Heck, I thought fiddle leaf ficus would be available all over the US. It has been rated as the #1 interior decorating plant for several decades, not years, decades. Open up any high-end, glossy, interior decorating magazine and you will almost always see the fiddle leaf. The fiddle leaf has a very interesting history and if you like you can read the article I wrote on ATP back in July, 2014. Oh, back to your air-layering questions. Yes, you are exactly right. No commercial grower will take the time and make the effort to air-layer plants. They can grow thousands from seed with no more effort than it takes to air-layer one branch.
I guess you saw that I started this thread because a friend asked me how to root camellia cuttings, and I had no clue. Thus, I asked. I did mention air-layering to him, but that was only because I air-layered that ficus. I had no clue whether that could be done with camellias.
P. S. I have a non-ending request for those air-layered fiddle leafs, and I will sell every single plant that I start that way.