Most of the COVID projections were off by a lot. The parameters reduced social distancing to a single scalar and often generated those values as outputs rather than genuine inputs.
I looked at various models over the summer knowing that while they may be wrong, they may be useful. But they did not help much at all for understanding trends and relationships. Take for example models that have been modified for mask mandates. During the summer, most of them had trended down to zero with masks “on” but the opposite has since happened.
There is a genuine amount of circular reasoning where models are used to validate social distancing efforts which in turn are incorporated into revised models.