"stablecoins" are not decentralized. If you're going to trust a central issuing and custodial authority for a coin, do you even need crypto technology in the first place?
Same with the "funding activists in repressive states" argument. Now you have a few centralized entities that can share data with the authorities. And they do, cf. Binance in Russia.
Ironically a CBDC from a powerful but non-cooperative state like China would probably be much safer for these people in Iran or Venezuela.