Let’s assume that there was no cash limit, a malicious government could still achieve the same result by changing the currency or even just issuing new notes an

Let’s assume that there was no cash limit, a malicious government could still achieve the same result by changing the currency or even just issuing new notes and instructing banks not to accept old notes. I guess you would have an underground economy for a while by those that are willing to be old-cash only, but good luck paying tax and other items that require the new currency/notes.