Currently I would put Barcelona ahead of Real Madrid. Because all the players of the Barcelona team play the match with great responsibility. On the other hand, if Real Madrid has a dedicated striker, I think the team will be complete.
Madrid is probably much more experienced in the UCL than Barcelona, even Barcelona failed last season, if you look at both of them playing well, just look at the domestic league at the moment Madrid is far superior with 3 wins in a row and established them at the top of the standings so it looks like they are right really consistent even though they have not found a striker who can replace benzema's position.
There are too many rumors about Mbappe being able to replace Benzema as a striker in Madrid, but it hasn't been achieved yet and the results are still the same. Madrid with the current squad is also sufficient according to Ancelotti, but we'll see how it goes, no one knows how the two will play in the UCL this season, but what I see in the domestic league is that Madrid is far ahead of Barcelona.