He definitely has the potential, no doubt about that. But in general, the Italian teams have been a little bad with their performance recently. I can say that because since the last 15 years or so they have not been able to win the Champions League competition. The Italian league in general Also faces a lot of problems as well. The corruption is probably a little too much. And for a player that is showing such talent as Osimhen, I think he should be in a much more competitive league. But of course, that also brings the question if Osimhen is ready for a bigger league or not. His fate could be very similar to Lukaku if he actually goes to the English Premier League. But life is nothing without risk. I am sure even Cristiano Ronaldo wouldn't have been Cristiano Ronaldo if he did not go to Real Madrid. but of course that is Cristiano Ronaldo I am talking about and this is not Cristiano Ronaldo 
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Regards
Duke
Indeed get extra quota for Serie A team get appearance in Champion League but almost longer time after Inter Milan winning the Champion League on season 2010/11 never any Serie A team become the winner almost ten years indeed last two season Inter qualified to final round but defeating by Manchester City. Some Serie A teams get financial trouble with small fund for signing new players and difference with Premier League or La Liga teams spent much money every window transfer opening. .Regards
Duke
Last huge transfer did by Serie A teams when signing Cristiano Ronaldo from Real Madrid, its make difficult for Serie A teams can play well in Champion League and last season the highest round by Serie A team at knock out round only.
Osimhen has potential become huge transfer for Serie A teams in this season as Napoli can sell him above 100 million euro, but need spend more bigger for Napoli signing top players and brave spent more if want get back to the top fourth standings position.