Not around here. I encounter many more fly anglers on the water than I did 10 or 15 years ago. The big growth has been with saltwater fly fishing. There are great year round fisheries here that do not require costly gear.
Many fly anglers here get started with saltwater fly fishing, most crossing over from conventional gear. Twenty years ago there was one local fly shop. There have been three for a out a half dozen years now.

There was a "Fly Fishing Show" in Southern California for several years. It not this year. They probably cancelled it for poor attendance. However compared to the other stops for the show, few vendors came and got booths to show their gear. So most people I know who went were disappointed. I know I was.