I agree with you. I think with Barcelona's current form and their financial status I think it will be very difficult for them to try to match Real Madrid. In fact, Real Madrid is the best team in the world at the moment and with Mbappe joining next season there is almost no doubt that they will become La Liga champions again next season. I think even Real Madrid can get a treble winner next season by winning the Copa Del Rey and the Champions League. Mbappe will take Real Madrid to a different level next season.
Maybe you are forgetting that even without mbappe, Madrid was able to win two trophies last season and was also able to attempt a trio so the whole thing isn't really centered around mbappe in as much as we do know that he's a really strong advantage to the team but Madrid may not have any form of dependency on him and that i see as very obvious because the team had a very good structure even before his arrival of which they can be shifted to him just because he's known to be very good with his role, they know like every football there will be times he will be absent too.
The success of Madrid in the coming season is definitely not going to solely depend on mbappe, most definitely he's going to play his role diligently which will in turn be beneficial to him just like the team will be benefiting from his good performance if he puts up one. Collectively both mbappe and Madrid are going to be of great benefits to each other but team work by other team members too cannot and should not be neglected at this point because it's very necessary and is a determining factor to the success of a player and the team as a whole by the end of the season.
Yes, Real Madrid is a club that has a great history and has won quite a lot of titles so that they are always respected by their opponents. Real Madrid is used to high level players. Mbappe's arrival certainly increases his strength, but he must be able to play collectively with other players so that Madrid's target of retaining the title is achieved. I am sure Ancelotti will treat Madrid players equally and not differently from one another. The honor of the club is more important than having to treat one player like a king.