That is true--the checks and balances the founding fathers fought so hard for were thrown out the window with overlegislation and expansion of prosecutorial discretion in 20th century. To make a convincing argument that "double digits" of cases involve fabricated evidence, you still need to explain why prosecutors would engage in fraud at this massive scale. Just laziness? Collecting scalps? The incentives run that way in some limited cases, e.g., prosecutor up for election, post-reconstruction south. But you need some explanation there.