I'm not much positive about Barcelona's chance to eliminate Napoli honestly. Because their game is just not good enough. I believe that they haven't faced a real challenge yet. Porto were the second strongest team in the group but Barcelona won against them twice anyway. But I think Napoli are a bigger challenge than Porto for them.
Napoli have a stronger squad in the first place. They have a very dangerous player like Osimhen in their offense line. They are just trying to improve their form lately. But until this matchup I think Napoli will be in a better shape than now. If Barcelona don't make improvement at the same time then they can really say goodbye to the CL early.
But I think Barcelona was lucky during this season of the Champions League because we know they are not in their best form and this Barcelona we currently see can definitely lose games easily against other teams. While Barcelona is also not in the form to face with stronger teams, however Napoli has players like Osimhen as you just said and since Barcelona's defenders are weak this can be dangerous.