On many airlines they use check-in as a way to try to upsell you on higher priced seats or other services.
During boarding, I have sometimes mentioned to the boarding agent or air staff that if someone in an exit row isn't able to perform the exit row duties, I'm happy to trade seats. A couple of times it's even worked.
Last time I had a flight I got a fairly good deal on a business class seat. That was quite nice.
Mind you these are people with immense authority. But like law enforcement.
If they tell you to do something, you do it.
And they’re telling you to sit down and listen to them sell you something.