With NFL overtime rules, teams hope to win the coin toss, score, and win the game at their first possession. This does not allow the other team to possess the ball.
With NCAA rules, the teams that win the coin toss usually decide to go on defense first because they'll know if the other team scored a touchdown, a field goal, or failed to score. Based on that, the team that goes second can choose to be more or less aggressive when they get on offense.
The NCAA rules allow equal chances for each team to score. The NFL rules do not. Does that create an advantage for the team that wins the coin toss?
CNN says that since the 2011 post-season, the NFL OT rule has been used a little over 160 times. And in the NCAA, since 2013, the OT rule has been used nearly 300 times in Division I games.
https://www.cnn.com/2022/01/24/sport/nfl-overtime-rules-chiefs-bills-spt-intl/index.html
Coin toss win results in OT win:
52% (NFL) vs. 49.7% (NCAA)
Coin toss loss result in OT win:
42% (NFL) vs. 50.3% (NCAA)
Those numbers make the NFL rules look unfair. Why not just declare the winner right after the OT coin toss?