The Madrid derby always presents a high-tension match, a draw is fair because Real Madrid always have a hard time when facing Atletico. This result made Real Madrid successfully extend their unbeaten record, but on the other hand Barcelona were very relieved because Real Madrid failed to reduce the gap with them. In the next match, Barcelona will play away to Alaves headquarters, Hansi Flick must be more careful when preparing his squad so that the same mistake does not happen again, they must be able to keep their distance from Real Madrid so that their position remains safe.
I don't think it was Flick's fault, all the changes for this match were not his fault, but because of injuries, so he just faced circumstances that he couldn't influence. It's hard to say whether Szczesny could have played better or not, but several goals were due to the goalkeeper's mistake, so this problem needs to be solved in any case.
If I'm not mistaken, this is the first match when Real played without Mbappe, he missed the match due to injury. Matches against Atletico are always difficult, and Real is just getting into shape now, so I expected that it would be difficult for Real to win, although Atletico managed to equalize the score only at the end of the game in extra time. Barcelona were lucky that Real couldn't win, so they maintain a three-point lead over Real, but instead they could have used this and increased their lead even more.