Of course they would rather then sign 34 year old Messi and not a young Haaland.
It is the logical answer and not disrespectful.
Haaland doesn't guarantee you anything, Messi pretty much does. He's been holding up this shitfest for three or four years now. With a solid defence behind him and a midfield who rarely get overrun, he'll give them greater success over two or three years than Haaland would over six or seven IMO.
Champions League is a rare commodity, if they want that the most, Messi is the obvious choice, and fans of their biggest rivals picking him shows how idiotic they are.