Remember the CB craze of the 1970s? It became insanely popular for a while
with a very wide audience, but then the sunspot cycle created horrible
conditions, and the faddists went somewhere else. The CB survived, though,
and even in these days of GPS and satellite and internet, there's still
nothing better for truckers and other interstate drivers than the old
familiar CB. I listen to channel 19 all the time, and it's just as busy as
ever before. CB is not about to go anywhere.

Neither is shortwave. I think shortwave is in a decline, but I think it will
survive and even flourish over the next few decades. I don't know who will
be on the SW band in 10 years, but I'm sure someone will be smart enough to
realize what a powerful medium radio can be.