Where is there a legal requirement to stay in your assigned seat? I've switched seats with people plenty of times on airplanes, or simply moved into empty rows. If you want to switch you can simply ask. (That is, if you're not afraid to talk to strangers!)
I don't fly as often as you. Maybe 6-8 times a year. But I usually try to travel on days/times/routes that I think will be quiet. Like, if I'm going to Vegas, I'll leave on a Tuesday night after a holiday weekend. Internationally, there used to be a lot of half-empty planes. Admittedly, I haven't seen as many empty rows since covid constricted the industry.
Did the people who you saw do this mid-flight/mid-unwanted-conversation, in order to escape their chatty neighbors, or was this more in the early phases of the flight when people were getting settled?
When people see my seat and see that it’s better than theirs, and simply ask me for it, sometimes I cave in in the interest of being nice. It’s cool that they want a nice gift from me, but even if I say a polite “no,” it makes me feel defensive about occupying a seat that I picked for a reason, under the same rules by which they picked theirs.
Usually early in a flight, and once it's established that there are some empty seats - that is, occupying an empty one rather than asking someone to switch. Although I once got on a 12-hour red eye flight that was full, settled in and, before takeoff, had a girl a few rows in front of me come back and politely ask the man next to me if he'd switch seats with her. She didn't like the company up there, I guess. He agreed, and she and I ended up hitting it off and sharing a hotel room at our destination. Which is admittedly a rather one-off situation...
I've also had the opposite situation, where I was desperate to switch but couldn't. The worst case was when I got the last seat on a flight and found myself between this completely asshole older couple where, it came out, the man would only fly in a window seat and his wife would only sit on the aisle. They bickered at each other over me for 3 hours as if I wasn't even there, and both refused to switch with me, going so far as to claim they both got airsick if they sat in a middle seat. Obviously, it wasn't even worth asking anyone else on the plane to switch, but I've never wanted to kill anyone as much.
