I’m assuming they do it because they want to be sure everything can fit in the space limitations and don’t have the time to consider case by case. Of course everyone takes things out of their carryons once they’re on board.. laptops, books, baby feeding stuff, blankets if you’re flying distance on a budget airline, etc etc. So putting it in a backpack to board and taking it out and putting it on your body when you’re on board seems totally logical to me.
2 Likes