Biggest problem with the Week 1 win vs Panthers?

And that backup QB was better than their starter, who has been God awful since his incidents.
The Browns won 8 out of the 12 games he started during the 2022 (3-3) and 2023 (5-1) seasons. The fact is that he hasn't played a lot of football over the last 3 years and played no preseason games this year. He's rusty. That doesn't mean that the entire team is doomed to be a 3 win team anymore than our blowout of the Panthers makes us a Super Bowl contender.