I guess I disagree with you regarding Lukaku and the category he falls into. Since Lukaku's game isn't primarily based on pace, I think he could be a valuable striker until he has reached a higher age. His game isn't as burdensome physically in terms of pace as is the game of Mbappe for instance. If Mbappe loses speed, his game will deteriorate one day. Lukaku could still be a player that is well needed in certain periods of a game, depending on the situation and the circumstances.
But I was rather pointing out that it is time for Lukaku to settle with a club he gets along with and Roma seems to be that place. There is no point in taking another risk and ending up on the bench again. But I guess he will go wherever he is paid the most.
Lukaku is player who does not have good speed like Mbappe, Theo Walcott, Bale, and his playing style depends more on his physical strength in face to face fighting with defenders. With his body, he usually slowly responses to situations when a ball suddenly finds him and he miss those chances.
However if you put Lukaku into his favorite system and tactics, he becomes very dangerous. Like he succeeded in West Brom, Everton, Inter Milan and now AS Roma. He failed in Chelsea and Manchester United but in contrast, he succeeded at two other Premier League clubs so in my opinion, it is not true to say Premier League does not fit with him.
I see that Lukaku is more fitted to Serie A because matches there don't rely on speed too much. It covers weakness of Lukaku and he can use his physical strength to beat defenders in Serie A better than in Premier League.