Most people don't spend money on things/do stuff when they are afraid of dying while doing so. Hundreds of thousands of deaths due to uncontrolled population spread, randomly (nearly) amongst the population is going to cause the economy to crater - and even the possibility of it already did before any lockdowns happened.

The lockdowns just stopped the 25% (guess) of the population that is going to YOLO anyway from causing even more damage. The businesses were still going to get a huge hit regardless.