Never seen Messi singled out anywhere to be fair, if anything the narrative everywhere is: "Imagine how much lower they would sink without Messi." A couple usual suspects on Barcaforum that want to create controversial discussions and pseudo online football connoisseurism don't even make up 0.1 % of the fanbase.
Everyone with half a brain cell knows at 33 years of age a player like Messi would need to have a proper team built around him if he was still supposed to deliver at a good level. Pirlo at 34 years of age did not move an inch off the ball, which is even more deadly for a central midfielder, but he had Marchisio, Pogba and prime Vidal around him. That's building around a player and mitigating his weaknesses.
Pairing Messi up with a horrible defense, shit midfield and 3 other number #10s upfront, coached by the guy who got sacked by Everton - then harping on about Messi not running around in defense as much as prime Pedro so therefore he is the culprit for Barca's woes is a clear symptom of mental illness in a vain act of trying to appear knowledgeable.