Trikes are making huge inroads in the recumbent area of cycling
Just look at youtube videos of the 2017 Midwest Recumbent Rally. Back in 2008 when I attended the MRR there were only a few riders on trikes. Now in 2017 it looks like at least half of the riders were on trikes.
Maybe this can be laid to the fact that the bent riders of the 90s and the 00s are getting older and going to trikes. It will be interesting to see how the bent scene shakes out in another 5 to 10 years.