Same thing happened in the 60's and 70's when quartz watches were so much cheaper and accurate compared to mechanical movements.
Mechanical watches will always be a niche market and will never go away. I'd rather have a watch that will last 50+ years and still look and sound good after that time. Take your pick, you got: Omega, Rolex, Breitling, Seiko, etc.. plus high end makers like Patek Phillip.
Sure the swiss watchmakers will go through their slump, but after the novelty of fancy usb charged smart watches wear off you'll always have the artistic mechanical movements of old.