There is a wealth of information on the subject in a new RAeS specialist paper:
https://www.aerosociety.com/publications/specialist-paper-emergency-evacuation-of-commercial-passenger-planes/
Cabin baggage is an issue but I think many of the problems come under the general heading of 'passenger behaviour'. Flying has now become so commonplace, and so safe, that people don't worry about their own safety and don't stop to consider the implications of their actions - though they will happily stop in the middle of an evacuation to get some juicy phone footage to boost their profiles on YoufTube or whatever.
I heard of one recent incident where a pax was removed from an exit row seat because they hadn't listened to the safety brief. If only more crews would do the same! Whenever I am in the cabin for departure I am always saddened to see how many pax ignore both the requests for them to pay attention and the briefings themselves. And for those who insist on removing their shoes before we have even left the gate, I always enjoy asking them how far they think they will be able to run barefoot through burning wreckage.
