We didn't win because we don't have an outball at the very top, meaning we are too often easily nullified if a side decides to shut up shop.
Today was exactly why Lukaku would be a flop at a giant club, because they play those games every week and rely on movement from the entire attacking unit to break teams down. We can't reliably play off Lukaku, meaning we can't reliably pick up form and thus consistent results.
It is also why we need to re-evaluate the approach to our squad in the summer, bring in a more technically gifted footballer with the brains to move and receive a ball and pull defenders out of position, because if we want to compete at the upper levels we need far more than just a goalscorer in that role.
If we keep Lukaku, fine, but we need that high quality plan B as a matter of urgency.