Science isn't just a game scientists play for fun; the scientific method is the correct method for making inferences and predictions. If you don't have enough information to make a scientifically/probabilistically sound prediction, you can't make an accurate prediction.
Sure the goal is to save lives, but if you don't have a robust, falsifiable and tested scientific model of what you're doing, you have no idea whether it will really save lives or not. For instance, the science suggests that harsh lockdowns did not in fact reduce mortality (did not save lives): https://www.thelancet.com/journals/eclinm/article/PIIS2589-5... . They did however contribute to significant excess deaths in under-65s; in Canada's case, more than the number of under-65s that died of covid: https://www150.statcan.gc.ca/n1/daily-quotidien/210712/dq210... .