Our troubles started the moment Abraham and Mount decided to stop scoring and Pulisic got injured. Sure, Kante returning from injury happened around the same time and although he has disrupted our midfield play and for some curious reason put Kovacic on the bench, it isn't his fault the attacking players can't seem to find the goal anymore. It isn't just few chances we've missed this season. I can easily point out 40 chances in the league alone, of which at least 20 should have been converted into goals. Had we done that, we'd be 2nd in the league not 4th, and this whole discussion wouldn't be even taking place.
Sure, we have also leaked A TON of cheap, soft goals. Usually those occur by the time our misfiring attackers have frustrated everyone in the stadium. Something has to be done about set piece defending and generally aerial defending inside our box and it's disappointing to see us make very little progress in this regard during the season. I do expect us to sign a CB and LB in the summer, but for the time being we'd be better off playing either Tomori or Zouma next to Rudiger rather than AC who just doesn't cut it in PL for me. Azpi also isn't a LB, and although I can understand Lamps shoehorning into the starting XI due to him being one of the few experienced leaders in the squad, he's just hurting our attacking play far too much.
TL;DR: We REALLY need a striker, and eventually better defenders too.