This disconnect is called the "Tullock Paradox" in Economics, after Gordon Tullock who first asked it in "The Purchase of Politicians" (1972) [couldn't find an online link].
You'll find a more recent discussion in "Why is There so Little Money in U.S. Politics?" (2003). [1]
Sometimes I think it's like dark matter, it's just out of the public eye in, I dunno, art sales or cushy jobs for family members that funnel money to one another.
TOO MUCH DARK MONEY IN ALMONDS (2019)
https://slatestarcodex.com/2019/09/18/too-much-dark-money-in...