You may also wonder how serious Messi's grief is that he has to leave the club. Last year he had already made the decision to leave the club, and at the last minute it fell through. If you really love your club so much, why would he want to leave last year? I think it's a stage. with Crocodil tears.
Next day he was cheering in paris

I seriously think that he doesn't care for the club "right now", of course he spent 20 years there, he came in as a very little boy and now he is a grown adult getting ready to retire in a few years I suppose (max 5 years but I doubt it) so it is normal that he has a huge sentimental feeling towards the club and that is what everyone would have expected from him, however that doesn't change the fact that he doesn't feel it for the club of right now.
The current Barcelona is not the Barcelona Messi fell in love with and poured blood and sweat, this is just the shell of what old Barcelona was. I honestly believe that it all started with Suarez leaving and subsequently Messi never felt home again there. Plus, if he was THAT much in love with his club, then he would take 1$ salary and stayed, they could sell some other players to cover the difference.