I do use probabilities, and in lots of different ways.
I put probabilities that other scientists have worked out into my models of disease spread. For example, scientists did an experiment to see what probability of people become sick with norovirus again 6 months after having it for the first time. I use this probability in my work.
I also produce probabilities, so for example the result of my work might be an estimate of whether something will happen, and how likely it is to happen. Probability, and uncertainty, is a big part of statistics and of my work.