Real Madrid showed that they are always stronger in the Champions League than in any other competition. I accept that the point gap is only a point difference, but Madrid still has a better advantage of qualifying to the the next round than Atletico. We might see a different game in the second leg, and Atletico performance might not be good enough to stretch the game to penalty shootout.
I also don't think that Real Madrid will give up in the second leg because Real Madrid usually can also put more pressure on the opposing team in the Champions League when they are in such a crucial round. So in the second leg there is a possibility that Atletico will feel much greater resistance from the team that has held 15 UCL trophies until now even though most people also admit about Atletico Madrid's greatness in La Liga this season, but when talking about the Champions League, this will be very different for any team.
No one doubts Real Madrid's mentality when playing in the Champions League, and victory over Atletico Madrid in the first leg even though only 1 goal is still a profitable capital for Real Madrid to face the second leg later.
If you look at what happened since previous seasons, of course there is a slight difference in performance when playing in the Champions League and La Liga, but sometimes a team also makes some mistakes, especially like Real Madrid currently who are having problems with the consistency of their performance, so I think it must be sorted between the competition in La Liga and also the Champions League.