You are answering like it’s 2015 and all you know about is how Bitcoin works. All 3 problems that you mention are solved with 1. zero knowledge proofs 2. multisigs 3. stablecoins.
That’s just wordplay, algorithmic stablecoins have been problematic and crashing since the beginning and a big one just crashed. Call me when USDC or DAI crashes - specifically not Tether because it’s arguably also undercollateralized.
USDT is a centralized stablecoin, same as USDC.
So in your argument that comes quite close to "No true Scottsman" fallacy, what is the exact criteria that you are using to separate out the "stable" stablecoins from the "unstable" stablecoins?