There is no reason why star names would work at Real and not Barca and the galactico era of Real is not seem as some huge success either.
Mbappe and Haaland would bring just as much to Barca together as they would Real.
Barcelona have almost always been one of biggest spenders in world football when had chance to do it and likes of Cruyff pushed for Ibra etc.
To make out Barca cant win with star players and it is not part of clubs history is completely false and based on this idea as if the one of La Masia generation was the norm.
Barca won last treble with best player in world..Messi. best and most expensive striker in world.. Suarez and best wide player.. Neymar.
It broke up but it worked.
You are conflating a lot of things.
Some useful distinctions:
1) Buying a big star DOESN't EQUAL creating a big star out of your own ranks
2) Spending money to strengthen the squad DOESN't EQUAL buying Galacticos. The criteria are much more strict in what constitutes a Galactico
3) Offering things on the pitch is one thing, and what happens with the status, authority, wages, influence on way of playing and all that baggage that comes with marquee signings is another thing.
finally, taking examples from Barto's stint does not prove a thing, because Barto distorted Barca way and ideology, simple as that.
PS: I don't get why everyone here quotes the failed Ibra transfer to prove something that is not the case.
Yes, it was a lot of money for a move that Pep himself corrected just 1 year after by booting him, but he was never gonna be the star of the team to begin with.
Mistakes happen, and that move was not typical or exemplary of Barca's transfer policy