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.
If they have high self-confidence, then of course they have great motivation. So, it seems it's not about motivation but yes, lack of self-confidence makes them not have a big winning mentality. Plus, they still don't have the management and squad depth to be at least as good quality. Therefore, it's no wonder that their team still failed in the Champions League and also, the Champions League is the highest trophy, of course, if they are not consistent, it is difficult for them to get the Champions League title and trophy.