Like you, I think Manchester City beat Copenhagen, especially with Kevin De Bruyne back. His skills improve greatly. I'm planning for the quarterfinals and beyond. City is strong but not invincible. They'll likely beat Copenhagen, but Real Madrid and Bayern Munich will be tougher. Those games will show if City can win it all. Football is unpredictable. It's not enough to have top players like De Bruyne; it's how they play together under pressure. That will decide if they can win Champions League again
Even without Kevin De Bruyne, the match against Copenhagen should still be an easy match for Manchester City because there is a difference in the quality of the two teams, although surprises may still occur when the favorite team performs badly because they slightly underestimate their opponent but on paper Manchester City's winning percentage is very big in the first match of this knockout round so that the quarter-finals will be theirs and City having Kevin De Bryune is a big advantage, that's why it is reported that the club has proposed a new contract for the player because there are reports that there are Arab clubs who are interested in him.
When Manchester City qualify for the quarter-finals, the match will be even more difficult because the team that advances to the quarter-finals will of course be a team that is more evenly strong and that will be enough to determine City's next steps whether they can qualify for the semifinals and final or will stop.