I wonder when and why conferences picked up the habit of giving out conference bags to attendees.
For the at least the first few conferences I attended, the bags had a clear function.
The attendee packet included a lot of paper, often more than could be tucked into whatever bag one was carrying. There could be several separate documents, such as a schedule grid and the printed proceedings. Carrying them around loose was inconvenient and risked losing some.
Providing a bag big enough for the attendee packet contents was a thoughtful gesture.