PSG is a very strong club financially but no matter how financially strong PSG is, they never want to lose money on player transfers. If a player moves to another club, the fee PSG receives for the player's transfer is a profit and PSG will never give it up. PSG spend huge amount of money to buy world class stars but due to their main focus on only world class stars they forget that world class attacking line up needs world class defense and midfield line up. If they hadn't forgotten this, they would never have bought world-class stars, they would have bought world-class stars and quality midfielders and defenders to make them a complete team. PSG is a team that has always failed in this perfection.
I don’t agree with you regarding the middle line, PSG has always had a very strong line, and the defense played poorly in some moments, because the team always placed the main emphasis on attack, and it is clear that in such cases their opponents tried to play on counter attacks, for defense it's always difficult. PSG have always spent a lot of money on players for all positions, their main problem still remains that the club owners have no patience, they simply do not give time to a new coach to form a strong team and change them every season.