I think Mbappe will not go to Barcelona. He joins the Real Madrid squad and if he has a choice, he will choose Madrid. Barcelona is still the same old, desirable, great Barcelona. They are still very prestigious, but they have problems with salaries and are in economically difficult times. If they were in a better economic period, then maybe they would have a chance with Mbappe. All we can say now is that Mbappe is still a big and powerful weapon for PSG.
Barcelona have signed several young players this season so I don't think Barcelona can sign Mbappe or Mbappe can leave PSG and join Barcelona. We have heard from the beginning that Mbappe is more likely to leave the club and move to Real Madrid. From where Mbappe is currently, every club will be interested in taking him but it remains to be seen which club Mbappe is willing to go to. Every time Mbappe was rumored to leave the club, Real Madrid came up.
Real Madrid tried several times to take this star to their club but for some reason that attempt was not successful but still Real Madrid is still hoping that they can take this star to the team.
Next season it will be confirmed which club Real Madrid will go to next.