Years ago, when the airlines first started charging for bags, we were on a full flight 737 from Orlando to Seattle. We got on the plane to find ALL overhead bins full and the FA actually instructed me to put my carry on CASE (average size 20” long with wheels, not a tote bag) under the seat in front of me. I spent the flight with my feet propped on top of it. Luckily I’m a small woman. I was pretty mad as I could see the bins stuffed with backpacks, purses, etc which should have been under seats.. I don’t think they had started gate checking bags back then, and we’re just overwhelmed. It wouldn’t happen today, I’m sure. I certainly wouldn’t let it happen now, lol.