You’re basically playing Let’s Make a Deal with the airline (or the GA). But it’s not exactly an “even” trade. The airline makes a proposal and the passenger’s choice is either to accept or decline it ,

Under game theory, if the proposal is exactly 50:50, then nothing would happen because neither side would perceive an advantage.

ln an oversell situation the airline gains by eliminating a seating problem and the pax gains by way of $$, a better seat , a better suitable schedule, or whatever. Both sides perceive a win.