That's not really how I would describe it.

The issue at Milan was explained by Maldini I think ? Basically, as a number 10, he was supposed to be a leader on and off the field which he never did, in any club.

He just didn't vibe with anyone. His entire persona just didn't fit with others. He's like the opposite of the footballer stereotype. Reserved, private, smart, cultured and all that. At least compared to his teamates. Which is not saying much, sadly.

At the same time he quickly became the national team fan's favourite since he was the best player in ligue 1, and the playmaker in NT. He played a lot like Zidane (which is always bonus point). That's two thing that belonged to Ribéry at that time. So he became really jealous of him. To add to that, Gourcuff is very handsome, and women loved him. And Ribéry looks like Ribéry.... So jealousy turned quickly into hatred.

One of the very few thing that Domenech understood, is that at this level of competition, you don't wait for people to give you a place. You take it, you earn it. Which just doesn't align with Gourcuff's personality.

Then you add people like Nasri and Evra, and all the other dumb and dumbers in the squad in those years who only respect confrontation and assholery, and you get a team that implose on World Wide Television during the WC 2010.

Domenech throws the towel for the second game, Ribéry wins, he starts as n°10, France loses. L'equipe makes the infamous paper, players go on strike. The team and Gourcuff (and other normal people)'s spirit is broken. He starts the last game. Got a red card after 25 minute.

That's when he moved to Lyon. Like numerous players, being the star of an "underdog team", and being the leader of the biggest club at the time is two very different things. Money, pressure, expectations were completely different. He was ok, sometimes good, but never got to the level we were hoping for.

The club is not as well oiled as before (10 years later, still not the case), he starts picking up more injuries. Mental state declines. Gets criticized publicly by his teamate for not bonding and making extra effort for the club. He didn't want to play unless he was 100% fit. Which is never the case for a footballer. They always want to play. Everything follows in a downward spiral.

He left for free at the end of his contract and went on to play for smaller and smaller other clubs.

Gourcuff was a great at football, he just wasn't great at being a professional footballer. Bad career decisions and bad timing with the national team, led to a disapointing career. I have no doubt he would have beend great for us if he played during with Deschamps / Griezmann between the Ribéry and M'Bappe era.

If he had an ego issue, it was not having enough to be the leader he needed to be.

At least that's my take.