Yep.
Basic aerodynamics says that most-efficient flight is well away from M=1. Clearly, nobody wants to go around the world at 200kn, you'll never get to half the places, so M~0.8 is the best compromise and all the really clever work is going into making aeroplanes cheaper, safer, and more environmentally friendly.
Above about, say, 0.85, the next best place to be is M=2+, but that presents all sorts of other problems.
So, to be honest, I think that in another 50 years, most air transport will still be around 0.8-0.9.
G