People talking about Leo further declining and thus being unable to compete in Copa 2024...He is already 36 ffs, he will be 37 next year and he won Copa+Finallissima+WC in a span of 2 years, who gives a damn about Copa?
Would be great seeing him with the Blaugrana for 1-2 more years and possibly lifting the La Liga one last time, but other than that, it would be 100% sentimental. He already was a shadow of himself in his last 2 seasons in Barcelona and could not influence big games, I doubt it would get better now that he is even older.
We wouldn't get 24 year old Messi all of a sudden. For all intends and purposes, he can come as a loan in 1-2 years time, maybe when the Camp Nou is ready, play for a few months so that everyone can say goodbyes and that will be it.