Look at cases per 100k population not positivity rate.
I think that each has value. In FL, we look at 2 different positivity rates: total test positivity, and new person tested positivity. This helps you see how many tests are from repeat testers like healthcare workers. Additionally, total tests administered helps put those numbers into perspective. All of that, in conjunction with the total cases per 100k population, will give you part of a picture. The rest is guesswork.