That chart of the owners of Federal Debt does not distinguish between different forms of debt and maturity. Most the Fed purchasing of debt has been in longer maturities, while troubles with bank solvency, money market funds and the general process of deleveraging has driven private capital and foreign invested capital into short term maturities with the goal of capital preservation over yeild. Private money, corporated operating deposits, and surplus earnings not invested are increasingly being placed into short term government security funds...so the charts do not give you a good picture about what is really going on because they aggregate all these important and discrete issues.
The process of deleveraging, deflation, itself is the process of moving capital from tangible assets and long financial assets into shorter term liquid accounts, cash being the most short term (demand debt) and short term treasuries being a cash proxy.