I understand the point you're making, but I'd like to add that even if you accept that potentially stablecoins might avoid some problems a (politically tainted)

I understand the point you're making, but I'd like to add that even if you accept that potentially stablecoins might avoid some problems a (politically tainted) central bank has, the issue isn't merely one of accepting that possibility, it's also one of lack of evidence and novelty. Having a bunch of private actors potentially run a huge experiment in which the economic fallout will not be born by them if it goes sideways is entirely unreasonable. I mean, that's kind of the whole problem with banks and their dodgy behavior, and this is no better; if anything it's even more risky since it's even less well understood and there's even less oversight, and fewer ways even a democratically elected government could intervene should the need and popular mandate arise. I'm all for running that experiment, but then with proper oversight, accountability, transparency, disaster planning, etc - and as much as possible without the conflict of interest caused by having those running the system own large stakes of it too; that's just asking for shady business.