Agnelli, who is also the president of the European Club Association, was speaking at the World Football Summit in Madrid and outlined his thoughts on the future of football.
And he explained why he believes Scottish football and others have dropped so far behind the superpowers of Europe.
• READ MORE - Uefa set to introduce third European club competition
He said: “If you go back and look at the winners of the Champions League or European Cup back then you find the winners were teams that you wouldn’t find any more today - clubs in big cities like Glasgow, Belgrade, Bucharest.
“So what happened? Well, we had the introduction of TV money and that has been a discriminating factor. Now, it’s not any more teams from the big cities, the discriminating factor became big markets.
“So I think about countries with great footballing heritage. I think about Scottish football, about Celtic, about the great Ajax team of the 1970s, Portuguese football too with Benfica.
“Tremendous countries, tremendous heritage... but slowly dying.
“Why? Because they haven’t got the market size. Scotland, Portugal and Holland to use these three examples simply do not have the market to compete with England, Germany, Italy, France or Spain.
“One third of football revenue comes from the 12 richest clubs these days.”
• READ MORE - The Celtic dressing room is divided, says Kris Boyd
And the Juve chief delivered another blow for Celtic, who were revealed last week as one of the driving forces behind the new third European competition.
Agnelli said: “It’s difficult when you look at a third-tier competition because there is very little commercial value, but sometimes we have to listen to our fellow club members who want to participate more.
“The fact that they are participating in international games would allow them to grow and showcase their players going forward.”