If all your co-workers are sick, shouldn't you be in quarantine as well? Or are you all working from home and they all still got infected?
Our company had it's own self created guidelines to that effect, among other things like telling all the workers when somebody inside the facility came down with it, at the beginning of the pandemic. It pretty much quit following's it's own rules a long time ago. Our place wasn't even closed that long in the very beginning because they used some mental gymnastics to consider themselves "essential" or at least a lot more than they really are. I heard from reliable sources that people coming back was more to do with the company running out of money (which granted was probably accurate) than an actual concern for safety. As far as any state guidelines or laws are concerned I have no idea. It's not the kind of place where the employees could reasonably challenge anything if nothing else than due to lack of resources anyway.
Now unless somebody is showing very clear symptoms that can't be hid or directly states they feel sick they basically don't care that much, and even then they will send just that person away to get tested. All testing is pretty much the responsibility of the employee to get done on their own. It's not like anybody is sent by the company on their behalf to get it done, so depending on how lackadaisical a coworker is or if they just don't care it can be quite a while before some of them will call back and give any information, assuming they don't just quit, which some of them have. I wonder how many of them just see it as a vacation for themselves. A lot of people will milk the situation for themselves and won't be in a hurry.
They haven't really been doing anything for people that might have been in close contact with other people to be frank. Then again I wonder what they consider "close contact". Depending on the way they choose to interpret it I could see situations where they could consider it be basically nobody else to damn near half the people in the place as much as some people move about. I'm sure they take an interpretation favorable to them.
Our very local area was also relatively lucky with the spread and have been spared the worst of it so far, but I think that luck has finally out. Luckily some vaccines have been out to the people that care to get them. I have a feeling the secretly are probably willing to be less lenient with the rules with people they know have been vaccinated already.