As others posted it’s packed with corporate, private, and or vendor run events that are not public. Several weekly.

The core of no public events is mostly due to cost. The event space is expensive compared to other potential options around the city. Festivals and other events have charity (and profit) aspects at times that another venue would garner better gains. Such as outdoors is always cheaper as there no HVAC or facility cost. I.e. many food festivals are held on church’s land outdoors that are donated.

Logistics as well. Downtown Convention center many times keeps some away as parking and other items in downtown (such as having to pay for garage parking).