I can imagine winning a lawsuit over contracting Covid-19 would be nearly impossible.
You'd have to prove that you know where you got it, and that the entity you're suing was negligent in some way that allowed you to get the virus...
At this point, it's a known risk. No entity is able to prevent it, nor protect you from it, nor even identify how much of the risk may be present in their establishment. So if you're in public, you're at risk, though it's nearly impossible to tell how much risk and by whom...