Perhaps another way to look at it would be that, as the quality of computers has increased, the total number of computers being made worldwide has also massively increased.

If we treat each computer made in the US today as equivalent to a thousand 1980s computers, then I'd hope to see the weighted data show that US manufacturing has massively increased as a result of making an exponentially larger number of exponentially faster computers. Rather than seeing it stagnate despite weighting each computer as worth so many old computers.