I recently realized that game theory favors ecash because the mints can't become central banks because they are basically over bitcoin and lightning rails. If there isn't a "central mint", this means mints are already incentivized to be completely trustworthy. If they aren't and expand their credit (mint more ecash from nothing) , their funds will be completely nuked because they will be fighting against big daddy bitcoin, the most prudent and resistant ledger ever created and also because the abundance of other mints that will be prudent(because they don't want to lose money)
To a more clear explanation of what I'm saying, look at this video from the minute 35: