It definitely isn’t like that.
I think Lukaku maybe had one injury of longer than a couple of games in his 4 seasons here. He was almost always available even when we played in Europe and he played midweek cup games. He was all of our goals and people kept saying somehow losing him would help us as we would spread goals around.
Anyone who thinks losing James is as bad as losing Lukaku has a serious misunderstanding of football. A 25 goal a season striker who has scored everywhere he has been, or a talented but constantly injured luxury player, with questionable attitude and professionalism. I find the reaction to James leaving over the top to say the least, and even more bizarre given how people reacted when we lost an actual world class goal scorer.
I know it's a little off topic, but you can trace most of our recent problems back to the day Lukaku left the club. We've never recovered since. If we had been able to build a side around him with the influx of cash, I reckon we'd be at least a lot better off.