Not to be a hater but Justin Sun is really a pro ponzi scheme artist. The introduction of USDD is timely aftet the downfall of UST meaning he just want to show off that with this move, he can overruled the fear by other investors on what happened on its fate. But literally challenged the system for what? People fomoing and mostly USDD supply probably is on his disposal.
It will take some time before it happened to tron, but if Justin will be careless like Do Kwon, its not impossible especially there are lots of whale hate Justin Sun.
We can not ask for decentralization in TRON and USDD at least now. At least so far, Justin Sun has better reserve for his USDD stable coin. He did not sacrifice TRON to save USDD. That is different than Do Kwon as he sacrificed $LUNA to save $UST. When both died, he changed his mind and say Terra is more than $UST. I can not believe in this guy.It will take some time before it happened to tron, but if Justin will be careless like Do Kwon, its not impossible especially there are lots of whale hate Justin Sun.
I would steer clear from any algorithmic stablecoin as they're prone to failure. Only collaterized and regulated stablecoins like USDC and BUSD have a future. Tether claims to be regulated, but its quite shady in its disclosure of USD holdings. Fortunately, regulators will be weighting into the stablecoin industry to minimize scams/frauds as much as possible. Who knows if this becomes the time for the cleansing of the crypto market? Just my opinion 
Algorithm stable coins are very risky. From their algorithm and from the concept to back a stablecoin by a very volatile asset. That is unrealistic. If you want to make a reserve to back a stable coin, the asset you use to back it should be a stable one. The best is US dollar because the mission of a stable coin is its peg 1:1 against US dollar. Best asset in reserve should be US dollar, not any thing else.Even gold is unstable and can not be considered as a safe backing asset in reserve and collateral.