Lukaku is one of the players who improves inter Milan's performance this season. Although inter Milan is also good, this season he is one of the players who helped the team reach the final zone of the Champions League, so it will be good if inter Milan signs him or extends his contract. If he really returns to Chelsea, I don't think he will be good or he can perform the way he did in inter Milan.
There are numerous players who are older than him and are still performing; Inter shouldn't assume that he can't perform next season either.
although Lukaku did quite well at Inter, he didn't stand out. last season he played 25 times in Serie A and made 10 goals and assists. after the loan contract is finished, it will be up to Chelsea. but the strongest news is that Inter wants to keep it by negotiating. As for the news from Milan, it has been denied by every agent. as well as news from the Saudi club, because Lukaku still wants a career in Europe.