When a new season starts and when different teams play a few matches in the beginning we get an idea about different teams and accordingly predict a team that this team can reach this level this season but everything can be said about Real Madrid. It's not just that Real Madrid have strengthened their squad this season, they always focus on strengthening their squad in all aspects. And the most important thing is that Real Madrid has consistency and each player has a good understanding with each player which is why they are successful in almost every match and they will be successful in the next season.
The description of the form of play is not only seen in the Champions League because there may be other factors such as consistency of play in the domestic league. Although sometimes that is not a guarantee for them to play well in the Champions League or vice versa for many teams. For example, Dortmund played not very consistently in the Bundesliga, but they managed to advance to the final round where they were ultimately defeated by Real Madrid. Likewise, Arsenal and Man City played quite consistently in the Premier League, but they failed in the Champions League.
There are many factors that make a team play more consistently, especially in the Champions League because the competition in that league is quite tight. Experience, mentality and players and coaches really determine how they are able to reach the end of the final as champions