I'm somewhat comforted by the fact that there are fundamental physical limits to computational efficiency[1] which we aren't at yet. MOSFETs look to be just about played out but there are tons of other potential computational substrates. Carbon nanotube transistors, photonics, nano-rod logic, magnetic coupling, DNA computing, etc. We're in for a big interregnum before we get a new paradigm working better than our existing one but there's no reason to believe that progress in computation is ending permanently now.
[1]https://en.wikipedia.org/wiki/Landauer%27s_principle