Absolutely, any stable coin that is centralized can lost its value at any time and I only knew one stable coin which is DAI backed by smart contracts of ethereum but as we know people prefer the tokens with liquidity so they just go with USDT even if there is risk of losing their money.
Wasn't DAI collaterized by crypto assets (particularly ETH)? If it's only backed by smart contracts, then it should be called an "algorithmic stablecoin" instead. TRON's USDD is one of them. But I get what you mean.
Decentralized stablecoins like DAI and USDJ are a much better choice because they lack a central authority/operator. This means the risk of loss is much lower than centralized counterparts. In the case of DAI, the stablecoin is governed by MakerDAO (a Decentralized Autonomous Organization). MKR holders can influence the future direction of the stablecoin. If USDT and USDC were like that, things would've been better by now. At least we have a choice. Who knows what would be the future of the stablecoins industry?