I must admit that it is the correct conclusion. Real Madrid's defense this season has been problematic as we have conceded 32 goals in 33 match. This is a bad statistic in recent seasons although Benzema and several other strikers have helped us avoid many defeats. You can compare it to the previous few seasons, so I won't argue about your conclusions.
Yes, it is a very bad stats, too many conceded goals. Ancelotti must strengthen Real Madrid defense if they want to compete for the La Liga trophy in the next season. This season, Real Madrid has failed to win the trophy due to defense and attacking problems. I think it is not only about the weak defense, but Real Madrid attacking looks not play consistently as well.
The number of goals conceded I noticed too, last season when they took the trophy, the number of goals conceded wasn't more than 31 in total for the whole season but this season is already 32 and some matches are yet to be played, that shows that Real Madrid has been unserious, the last time they had something similar with this number of conceded goals were 2018/2019 and they ended in the third, they are simulating this pattern this season.
Benzema, Vinicius and Rodrygo have all had good form this season, but when our defense is in trouble, it's not going to help us in our title race this season. In the end Real Madrid had to admit defeat in the title race with Barcelona, so all of that must be corrected next season.
They may have performed well, but they can't always be in good condition. Benzema often gets injured, so he can't play in some matches. This makes a problem since Real Madrid gets difficulty in scoring without Benzema. Ancelotti must try to add more top strikers for the next season.
I don't think defenders are only the problem, the forward has also relented on the goals they score. Rodrigo was fair but Vinicius and Benzema decline this season. No players come close to the number of goals Benzema had last season, even in the Champions League but look at what they are playing this season, they played as if they weren't the ones that made us proud of Spain last year.