USDT can collapse in a way nothing will happen to crypto industry, my reasons are

1. USDT is said to be owned by an exchange bitfinix which was hacked few years year and believe to have manipulated tether to pay their Dept
2. Knowing that their are government organizations that are investigating this, although it can be underground
3. Tether is not only the stable coin, it can be delisted on exchanges and be replaced by other stable coins.

Only coin that can collapse and result to the collapse of crypto industry generally is bitcoin, but this has not be seen to happen.