I tried to go bagless on one trip. My kids each had a messenger bag for their stuff (which meant I had to wait in line with them anyhow). I realized that I had been carrying around everyone's stuff while all I needed was a wallet and a cellphone (which easily fit in my non-cargo pant pockets). So, we were waiting for a parade, and DD#1 put her bag on the ground. Then we decided not to watch the parade, and we left the park. On the bus to OKW, we realized that DD#1 was missing her bag. I called lost & found, and as soon as we got back to the resort, I hopped on a bus that went back to DHS. It turns out that miraculously, no one had touched her bag. It was sitting right where she had left it.
After that debacle, DH declared that mom had to be the family sherpa and that kids are not allowed to have their own bags.
Though, now that the kids are older, we may try it again this year.