They WERE.
Still are.
I posted a link to a listing of every state and some of their quarantine regulations.
In 3 states it’s a straight up felony to break quarantine.
Use of force is authorized under every state penal code to enforce quarantine. Even though the penalty for breaking quarantine varies from misdemeanor to felony.
That means if you are dumb enough to resist, they can hurt you. The more you resist, the more hurt you get.
Of course everyone is free to challenge these orders in a higher court. But getting there might take months and months. Once you get there it is likely the ruling would favor the government due to properly enacted law and “emergency”.
It’s not a good idea for anyone to violate quarantine, or, especially, to resist its enforcement. You’re not likely to enjoy the outcome.