They're comparable in that they're both obviously attack orientated fullbacks with a penchant for being caught out defensively.
But that's not true. It's lazy, tired bullshit. it's like saying Andros Townsend and Sterling are the same because they're both English wingers.
Alves is a great defender for modern football. Doubly so in a Guardiola team, where he's defending space, he's pushing wingers back into their own half because they are struggling to deal with him, he's superb 1v1, and he knows exactly what position to be in. He's brilliant at stepping into midfield and winning the ball back before an attack can start, or even to make sure the ball isn't lost in the first place. He is an outstanding defender for any team who considers themselves to be possession based.
Difference between Barcelona with Alves and Barcelona without? Conceding 30% more goals.
Maicon, yes, he would push up and then rely on his pace and physicality to make up for mistakes, in many ways like Walker before Pochettino got his hands on him, but that's why he was gone so quickly, being one of the best in the world for only 2 years, he had nothing upstairs, he was figured out.