Public debt is just bonds, i.e. the private sector savings. Why is it problematic that the private sector has savings? Why would we need to inflate that away,

Public debt is just bonds, i.e. the private sector savings. Why is it problematic that the private sector has savings? Why would we need to inflate that away, rather than letting it continue to exist to support people during their retirements? Private savings (public debt) is not inflationary, private and public SPENDING is inflationary. If it's too much for the capacity of the economy to absorb it, then it bids up the prices goods (demand pull). If the economy is running below capacity and extra funds are injected to facilitate demand, then economic activity revs up to meet the extra demand. As to the CPI, I'm sure it has its flaws, but I'd trust it more than a website offering $150+ newsletter subscriptions. The CPI changes over time because people buy different things, and tying inflation estimations to a static set of goods carries its own problems.