That seems a very subjective standard. Personally I find modern computer power a lot more impressive than any dang highway, however cheap. The Romans had highways. And before you accuse me of cherry-picking, they had steam engines too, and railroads. Drawn by elephants because it didn't occur to anyone to make a steam engine do it.

Yes, it is difficult to make these comparisons, but let me try. Most of Silas's examples were telecommunications. I think the incremental improvements in telegraphs 1850-1900 trump computers in changing the world. The incremental improvements in radio and telephones 1900-1950 probably don't. I don't expect to convince you of those comparisons, but they are swamped by a lot of other things 1850-1950, in contrast to practically nothing else 1950-2000.

I'm not sure what your point is about the Romans. I guess by the standards of "fundamental breakthroughs" steam engines get credited to them, but by Silas's standard, they largely get credited to the first half of the 19th century. Railroads to the second half, and that's what I'm talking about.