How often do you come across these confused passengers that have decided not to sit in their assigned seat but rather something better?
I come across them several times a year and, most recently, on a British Airways flight from Dubai to London. As I was the last passenger to board the plane, I had a look at the cabin and saw this gentleman in my seat.
I never deal with these seat poachers personally but instead have a flight attendant fix the situation. The seat assigned to this person turned out to be one of the middle seats that could be acceptable for a couple of friends but not for two strangers.
You should not switch seats before the boarding is completed and the doors closed. Even then, you may want to inform one of the cabin crew members of your intention.
I have never come across a situation where my assigned seat would have been inferior to that of the person who has decided to sit there. Isn’t that surprising and confirmation of the type of passenger “confusion.”
There were no good seats left when I switched to this flight from an A350 and one with a new seat. I had to do this at the last minute due to some meeting changes.