Kante was key in Leicester City's Premier League success last season, while the France international has been one of Chelsea's standout players this term as the Blues close in on the English title.
A number of pundits have claimed that Kante should be awarded the PFA Player of the Year for the 2016-17 campaign, but Barton has said that the 25-year-old is simply 'in fashion', just like Dimitri Payet at West Ham United last season.
"In England, there are boxes and it is impossible to get out of them," Barton told Le Journal du Dimanche. "At the moment, for example, everyone swears by N'Golo Kante. It's fashionable. For pundits, he's the best midfielder in the world. That's not the case – he's very good, but I played against him three weeks ago.
"He's a phenomenal destroyer who played in a phenomenal team, but he's not a creator. And it's impossible to be so definitive with a player who has not played in the Champions League. Two years ago, no-one knew who he was and I was surprised that the scouts missed him. I'm sceptical, like Dimitri Payet.
"He was incredible last season with West Ham, which surprised everyone, including me. When I was with Marseille and he played with Lille, he was only seen against Sochaux and Brest – never in the big games. It was the same with OM afterwards."
"But in England, it was different after his first game. Except, no big club made a move for him: it was China or Marseille? Why? We focus too much on a player when he works well, we don't focus on how he behaves in difficulty. If you look at Zlatan Ibrahimovic at PSG, he was very consistent – that's the mark of a great."
Kante, who was relatively unknown when he arrived at Leicester from Caen in the summer of 2015, has scored once in 27 Premier League appearances for Chelsea this season.