I think there may be a third option: people recognize both that the risk is low and selfishly they need not change their behaviors, but they also recognize that

I think there may be a third option: people recognize both that the risk is low and selfishly they need not change their behaviors, but they also recognize that the socially correct behavior is to change their behavior so in aggregate we lower risk. I do believe that the risk is fairly low right now. So low that if I'm only thinking of myself, there's not sufficient justification to change my behaviors. However, I also believe that if no one changed their behaviors, the risk would be high enough I'd have to (as is the nature of an exponentially spreading thing). As such, I behave how I need everyone else to: I change my behaviors in the hope everyone behaves similarly to me. For a very similar analogy, there's no need individually to get vaccinated risk wise. Developed countries have such a high level of vaccination that there's a vanishingly small probability you're exposed in your entire life to the things you're vaccinated against. There's a higher risk of side-effects from being vaccinated. However, if no one got vaccinated, the math doesn't work out anymore, and it's back to vaccination making sense for you as an individual. As such, most people get vaccinated since it's the socially conscious thing to do, it's what we ourselves need most other people to also do for our own health.