Recently, Rob Sherwood gave an interesting video presentation on disruptive technology in our hobby. In it he quoted the number of ICOM IC7300 transceivers sold in the first year. If I recall correctly, 11000 (ish) were sold in year one. Apparently, this is good. If the IC7300 SDR based radio sold this number, I'd guess Yaesu and Kenwood sold far fewer of their units.
Incidentally, when I was involved in radio pager design in the late 1990s, we made this number in one day!
As we get older, we can expect the numbers to fall away. People die and fewer new rigs get sold. In the end the Japanese manufacturers will decide it is just not worth their while as the profit margins are too small. Expect progressively fewer new models as the years go forward.
OK, in some countries there are younger people entering the hobby, but certainly here in the UK amateur radio is an old mans hobby and in 20-30 years we'll be gone.
One thing we'll see is cost cutting. There will be a move to SDR technology, as this will allow good performance for less money.
Expect dealers to dwindle and there to be fewer radio magazines. The hobby will be quite different in 2040.
Once again, I am grateful to Southgate News for this link.
See http://southgatearc.org/news/2017/june/disruptive-technologies.htm#.WTVAW7pFzIU .