Yes, I am afraid they are, and it is inevitable for reasons already stated.
Those of us who are old enough have many happy memories of great shows, here and abroad. I went to my sixth Oshkosh, Wisconsin, show last year, and, as I am not a photographer, decided that there was nothing new to entertain me, so I have closed the door on virtually all Airshows, except for Rougham, in Suffolk, which was a magnificent show last year, and is local, as is Duxford, which I would never miss.
Going to Airshows was a hobby for a number of years, and reulted in my travelling to many places, including Lightnings in South Africa, Russia, Israel, Venezuela etc.,
Guess I have got a bit bored with grey F.16s etc, and now prefer to see the best flying in the world at Duxford shows. [Flying Legends coming up soon!!!] The future of more variety doesn't look too encouraging I'm sorry to say. Great times in the past.