The astounding growth in the rate of publications (the chart I linked to) could not have arisen without a tremendous growth in the number of people, and in the funding. I don't think growth can be achieved without a decrease in overall quality of contributors / contributions, and indeed I wouldn't be surprised to see lower funding per author.
Could you show any data that supports the claim about nearly exponential growth of funding for academic research?
AFAIK the funding, especially considering growing number of people in the field, gets rather worse than better.