I fly reasonably frequently across Europe on BA and I'm often on flights that consist of waiting for hand luggage to be stowed before we can push back.
On my trips I usually pack a small bag that goes under the seat infront. Rarely I'm away for a few nights more and I need to pack a small rollaboard, but then I only take that and not the smaller bag.
MUC - I have routinely found to be full of pax with a rollaboard and laptop bag each as minimum, then add duty free. There just isn't the space for everyone to do so. I have been onboard a MUC flight and lost a slot before while waiting for bags to be stowed.
AMS & DUB are similar. Just way too many large cabin bags.
PRG - last time I flew this route I spotted a chap with a rollaboard + laptop bag + rucksack + duty free. Then.... he wife and kids appeared and they all had several bags too. watching them try and fit all these bags into the overhead actually became comical.
Returning from ARN last week, there was a family of four people and ALL of them had a rollaboard and a back pack - they couldn't fit it all in the overheads and asked the crew to store some bags upfront. The crew advised that they couldn't and extra bags had to be checked. They made it fit by moving someone else's bag. I despair
Off to BCN today, lets see what carnage awaits....