Agnelli, 37, the fourth member of his family to run Italy's most successful domestic club, said Italy had stagnated as a football country in the last year and Serie A was now a shadow of the glittering jewel it once was.
"If you go back about 10 or 15 years, it was the dream of every international footballer to come to Serie A," he told delegates at the Leaders in Football conference at Stamford Bridge.
"It was the destination for top players. When I was a kid studying here in England you used to watch live Serie A games broadcast here. The English League was not what it is today.
"Now the German League is building on what it has achieved in the last 10 years, the Spanish League has its own unique environment and has two of the world's most successful worldwide global brands, Real Madrid and Barcelona.
"France has benefited from overseas investments."
Agnelli said that from a football point of view Serie A was no longer the final destination for players but a transitory destination.
"Where will we be in two or three years, will we be able to keep players like Paul Pogba, for example? I don't think we have the economic strength to retain such a player.
"Look at AC Milan, they had to give away (Zlatan) Ibrahimovic. We need to have greater economic strength."
Italy has slipped from second to fourth in the UEFA coefficient ranking system since 2006, meaning it has only three clubs in the Champions League instead of four.
Last season they only had two teams in the competition proper because Udinese lost in the qualifying rounds, and although Juventus reached the quarter-finals and earned 65.6 million euros ($88.7 million), Agnelli is still worried about the future.
"It was an anomaly that we earned that much as the Italian market pool is so big and was set up when we had four teams but last season was split between two teams (Juventus and AC Milan)," he said.
"But you must be in the Champions League because that is where you have the international exposure.
"However, we need reforms in Italy. We have to look at our stadiums, that is where the difference is made, on ticketing and on income streams. That is our No.1 reform, and that is where the broadcasters come in.
"If we have a good show in the stadium and show it off to the full, that is the way to increase the broadcasting income, and that is just the start."
Agnelli has overseen the transformation of Juventus's home ground from the unloved Stadio delle Alpi which was built for the 1990 World Cup but demolished to make way for the 41,000-capacity Juventus Stadium on the same site.
The year 1990 is a pivotal moment in Italy's story.
Although they have since won the World Cup for a fourth time, in Germany in 2006, Serie A and the game have rarely generated the levels of optimism that existed around the time when the Italians hosted the 1990 World Cup.
In 2007 Italy bid to host Euro 2012 but lost out to Ukraine and Poland, and Agnelli is convinced it will be some time before the country is again seen as a football powerhouse.
"We were not effective in UEFA and our bid was not good enough," he said. "It was a chance missed to regenerate our stadiums and our game.
"If Italy goes and bids for something, Italy should get it. "But our federation needs to increase its standing. Italy has lost its leadership. England, Germany and Spain are ahead of us.
"Our League has lost its drive and we need to spend a lot more time thinking about how we can improve domestically and internationally."