I think if given the choice in my opinion PSG is better than Napoli. They can almost always win the league so they will always be able to play in the UCL almost every season. But the problem is that currently PSG is not a good choice if you want to have a career. They are a good team but Ligue 1 is not as competitive as some of Europe's other top leagues.
Well I don't really know if PSG is far better than Napoli because the both teams are currently playing on different leagues that has different levels of performance but if we should consider based on the local league achievement is obvious that PSG has more to offer than Napoli because they have been wining the French league for seasons now and it has become a thing of habits for them because no matter any difficulties they would always win at the end.
But however in the case of Napoli is always very difficult for them and they even barely qualify for any league before the season runs out, well I wouldn't blame them because there is a huge difference between Italian league and French league because Italian league is difficult to play than French league because if PSG should play on the Italian league there is no way they would perform the way they are performing.