Real Madrid are coming for every major titles next season, they keep adding players with impressive stats and we know it's improvement for them. Carlo Ancelotti have potential talents in his squad and he will frequently make good use of them in matches and also tough games. Jude Bellingham and Arda Güler are tender and are already playing like professional footballers, this is a good contrast for Real Madrid, these players just have to developed and come out in good styles.
Carlo Ancelotti can set a target of three trophies at once next season because he really realizes that the team he coaches is capable of doing a lot in several competitions next season. So setting a target of three trophies simultaneously in one season is something that is very feasible for Real Madrid with the squad they already have. And I think it could be successful for Real Madrid next season if we refer to the players that Real Madrid currently has.
The problem with 3 cups in a season is that there are A LOT of games in a season, and some of those cups are just about having one loss and you are out, unlike the league. There are 38 games in the league itself, there are like what 7 or so games in the cup? Maybe more, I am not sure. On top of that they have 8 games in UCL this season just at the group situation and then there are after group games, there are quarter finals games and semi finals games and final games etc etc.
When you think of that there are probably at least another 15 or so games at the UCL as well if you want to win. When you calculate this all, we are talking about sixty or so games. You can't expect players to play sixty games in a season, and you are going to have them tired, and one loss could mean good bye to a cup.