Has the practice of martial arts jumped the shark? Is it on a downward trend not to recover? Did Brazilian jujutsu and mixed martial arts kill traditional budo?
I used the Google Ngram service to see what people are writing about martial arts these days.
It looks like participation in all types of martial arts is dropping. However, MMA also appears to have taken a downturn, which means it is not the traditional budo, per se, that are threatened, and aikido seems to be on less of a roller-coaster ride than, at least, karate.