Indeed. Arsenal meets the criteria of the dream team of Osimhen. Arsenal is competing for the EPL title, they are also playing in UCL knock-out phase. Arsenal has the chance to win the title of 2 popular competitions, specifically for EPL title. If Osimhen wants to join Arsenal, I believe Arsenal to be a more stronger team in the future.
If Chelsea and Arsenal recruit Osimhen, they will definitely have to pay a lot to Napoli in the transfer market. Chelsea also needs an attacker who is aggressive in scoring lots of goals and Osimhen is their target. We'll see whether Osimhen will stay with Napoli for a long time after accepting a new contract offer or whether he still chooses to leave. He is quite a valuable asset for Napoli and he will be a big star if his intention is to stay with Napoli.
I understand if Osimhen would like to leave Napoli and go to Arsenal as that opens the door for him to the best league in the world and to play in the Champions League next season. I doubt that Chelsea will qualify for the Champions League. It could still be a great adventure for him and I guess he would earn more than he currently does at Napoli, but it would not be real progress for him. Chelsea is not one of those clubs that dominate European football anymore. But it would make sense if he misses the CL with Napoli and has to leave anyway if he wants to go to the Premier League, but would Arsenal really be interested in him?