The case of PSG with lot of quality players with nothing to show for it at the champions league is the same as what happened to Chelsea this previous season. Too many talented players but couldn’t put them into good use becomes a wasted effort and resources by the club.
Chelsea don't have many talented players, but they have many overrated players and they make it worse by spent higher than the players' market value.
The problem of PSG they only have few talented players and their opponents are weak, so when they always win in Ligue 1, there's no club can become their rival to learn and improve their club. Lack of motivation and overconfident are the big enemies for club which is already in top position, Arsenal is one of them.