Of course going to PSG would have being the best for him because he will have the chance to play in Champion League all the time but that does not mean that he will have the chance of winning UCL because when PSG had the players which are Messi, Mbappe and Neymar PSG was unable to win UCL. Only Khvicha Kvaratskhelia will not be able to make PSG win UCL. Napoli is a good club and maybe he wants to play under Conte and hope that Napoli will qualify for UCL next two seasons so that he can display his potential for another big club to buy him but not PSG.
Currently Osimhen and Kvaratskhelia are targets of PSG and PSG are even ready to pay 200 million euros to get these two players from Napoli, but So far the most difficult conditions are of course for Osimhen after he has been rumored to leave for a long time but none of the clubs have looks serious about bringing him in, Napoli will not sell Kvaratskhelia at this time because they still need him in the squad next season, but in fact PSG currently also don't want to buy Osimhen without Napoli wanting to sell in a package with Kvaratskhelia, in fact if Osimhen goes to PSG next season then it is certain that every season he will will continue to play in the Champions League because no other team in Ligue 1 has the ability to dominate the league for this long time.
I don't think so, now we shouldn't compare in the domestic league, that's not fair but compare the performance and achievements of the team in the Champions League in the last few seasons and it is clear that PSG is much better than Napoli so the decision to move to PSG is a step forward for development career Khvicha Kvaratskhelia.
Besides, Napoli under Conte won't necessarily be successful, so don't overdo it.
So far PSG have only failed to win the Champions League but they have not failed in competing in the Champions League so far, If we compare it with Napoli it is clear that Napoli is still far below PSG so far if we compare their achievements in the Champions League, apart from that, if Kvaratskhelia and Osimhen able to bring PSG to get trophy champions league for the first time in the team history, won't they experience a fantastic increase in selling value and will certainly continue to be remembered as PSG heroes in the future.