COVID risks are directly related to behaviors.
Example: I live in a college town, with many students starting their studies for the year in late August. I'll over-simplify to discuss just students, and two student types:
Type 1: Recognizes COVID dangers and precautions, attends classes online when possible, participates in unavoidably "in person" learning (for example, laboratory classes for science courses) with safety protocols in place (mask, distancing, etc.). Leaves campus when required classes are over. Sadly, college is not as much fun as when mom and dad attended college. Stressful.
Type 2: May do all of the same things as Type 1 during class work/study time. But, wants to have the fun college experience. Gathers maskless in large groups for parties, at local bars, music venues, football games, etc. It is college after all, why not have fun? Routinely goes from campus to home, visiting family and friends (also maskless, no distancing). Family visits included that week he felt under the weather, with a cough and fever.
In the USA, COVID spreading at colleges is rampant now, nearly all of the spread associated with "Type 2". The spreading extends when the student heads home, for just a visit, or when the student falls ill.
Some modelers have predicted 400,000 deaths in the USA by January. We are near 200,000 now.