You are emotional.
You would play Messi just because of his former self and not because what he is offering currently.
Suarez was an awesome player 5 years ago.
Should he still play for us because of sentiments and past times? No.
Busquets was a part of our best team.
Should he still play because of that? No.
Griezmann was once an awesome player, but he mostly sucks for us.
Should we play him because we paid 120M for him? No.
Why is Messi different?
Should we give him a credit for the next 5 years because he is Messi?
His current displays are not bad.
They are atrocious.
And if our RB Roberto sucks, our team can still play well inspite of a RB.
But if a key man, who gets every single ball, is ruining an action after action, then it is a huge problem.
I usually don't like when people say: "Just play any player instead of XX, it can't get any worse"
But seriously, a current Messi is ruining so much that I would like to play anyone else for a few rounds, because I doubt that we could be more unbalanced than currently.
And not to mention fielding 11 players who can run, move and pass.
Like Alba-Araujo-Pique-Dest, Frenkie-Pjanic/Busi, Ansu-Cou-Griezz-Braithwaite.
I can't see how that team could do worse than a current team.
4 players in the attack would finally combine freely and they would have several options in each action which would make us more fluid, unpredictable and dangerous.