I am pretty damned certain that the "important problems" being referenced here, and the ones we thought we would be able to affect in the heyday of computing, were not "we need to learn how to make a faster compiler" but "we are going to change the world". You seem to have conflated "interesting" with "important".

If anything, we agree on one point: that computers failed to solve those problems, and where we thought they would--Twitter being a great example--they quite arguably made the problem much much worse.

That is why I will argue computers feel so much more depressing today: we have been slowly coming to the realization--not just in the past few years but since at least the 50s (if not the turn of the last century)--that the entire concept of a utopian technofuture is probably a fantasy and dystopias now seem so close that we barely find the idea compelling to talk about anymore.